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Python
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     Python 3.10.12, January 17, 2025

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     Copyright © 2001-2025, Python Software Foundation

What’s New in Python
The Python Tutorial
Python Setup and Usage
The Python Language Reference
The Python Standard Library
Extending and Embedding the Python Interpreter
Python/C API Reference Manual
Distributing Python Modules
Installing Python Modules
Python HOWTOs
Python Frequently Asked Questions
Glossary
About these documents
Dealing with Bugs
Copyright
History and License
Distributing Python Modules (Legacy version): Distributing Python Modules Legacy version.
Installing Python Modules (Legacy version): Installing Python Modules Legacy version.
Python Module Index
Index

— The Detailed Node Listing — What’s New in Python

What’s New In Python 3.10: What’s New In Python 3 10.
What’s New In Python 3.9: What’s New In Python 3 9.
What’s New In Python 3.8: What’s New In Python 3 8.
What’s New In Python 3.7: What’s New In Python 3 7.
What’s New In Python 3.6: What’s New In Python 3 6.
What’s New In Python 3.5: What’s New In Python 3 5.
What’s New In Python 3.4: What’s New In Python 3 4.
What’s New In Python 3.3: What’s New In Python 3 3.
What’s New In Python 3.2: What’s New In Python 3 2.
What’s New In Python 3.1: What’s New In Python 3 1.
What’s New In Python 3.0: What’s New In Python 3 0.
What’s New in Python 2.7: What’s New in Python 2 7.
What’s New in Python 2.6: What’s New in Python 2 6.
What’s New in Python 2.5: What’s New in Python 2 5.
What’s New in Python 2.4: What’s New in Python 2 4.
What’s New in Python 2.3: What’s New in Python 2 3.
What’s New in Python 2.2: What’s New in Python 2 2.
What’s New in Python 2.1: What’s New in Python 2 1.
What’s New in Python 2.0: What’s New in Python 2 0.
Changelog

What’s New In Python 3.10

Summary – Release highlights
New Features
New Features Related to Type Hints
Other Language Changes
New Modules
Improved Modules
Optimizations
Deprecated
Removed
Porting to Python 3.10: Porting to Python 3 10.
CPython bytecode changes
Build Changes
C API Changes
Notable security feature in 3.10.7: Notable security feature in 3 10 7.
Notable security feature in 3.10.8: Notable security feature in 3 10 8.
Notable Changes in 3.10.12: Notable Changes in 3 10 12.

New Features

Parenthesized context managers
Better error messages
PEP 626; Precise line numbers for debugging and other tools: PEP 626 Precise line numbers for debugging and other tools.
PEP 634; Structural Pattern Matching: PEP 634 Structural Pattern Matching.
Optional EncodingWarning and encoding="locale" option

Better error messages

SyntaxErrors
IndentationErrors
AttributeErrors
NameErrors

PEP 634: Structural Pattern Matching

Syntax and operations
Declarative approach
Simple pattern; match to a literal: Simple pattern match to a literal.
Patterns with a literal and variable
Patterns and classes
Nested patterns
Complex patterns and the wildcard
Guard
Other Key Features

Simple pattern: match to a literal

Behavior without the wildcard

Patterns and classes

Patterns with positional parameters

New Features Related to Type Hints

PEP 604; New Type Union Operator: PEP 604 New Type Union Operator.
PEP 612; Parameter Specification Variables: PEP 612 Parameter Specification Variables.
PEP 613; TypeAlias: PEP 613 TypeAlias.
PEP 647; User-Defined Type Guards: PEP 647 User-Defined Type Guards.

Improved Modules

asyncio
argparse
array
asynchat, asyncore, smtpd: asynchat asyncore smtpd.
base64
bdb
bisect
codecs
collections.abc: collections abc.
contextlib
curses
dataclasses
distutils
doctest
encodings
fileinput
faulthandler
gc
glob
hashlib
hmac
IDLE and idlelib
importlib.metadata: importlib metadata.
inspect
itertools
linecache
os
os.path: os path.
pathlib
platform
pprint
py_compile
pyclbr
shelve
statistics
site
socket
ssl
sqlite3
sys
_thread
threading
traceback
types
typing
unittest
urllib.parse: urllib parse.
xml
zipimport

dataclasses

__slots__
Keyword-only fields

Porting to Python 3.10

Changes in the Python syntax
Changes in the Python API
Changes in the C API

C API Changes

PEP 652; Maintaining the Stable ABI: PEP 652 Maintaining the Stable ABI.
New Features: New Features<2>.
Porting to Python 3.10: Porting to Python 3 10<2>.
Deprecated: Deprecated<2>.
Removed: Removed<2>.

Notable Changes in 3.10.12

tarfile

What’s New In Python 3.9

Summary – Release highlights: Summary – Release highlights<2>.
You should check for DeprecationWarning in your code
New Features: New Features<3>.
Other Language Changes: Other Language Changes<2>.
New Modules: New Modules<2>.
Improved Modules: Improved Modules<2>.
Optimizations: Optimizations<2>.
Deprecated: Deprecated<3>.
Removed: Removed<3>.
Porting to Python 3.9: Porting to Python 3 9.
Build Changes: Build Changes<2>.
C API Changes: C API Changes<2>.
Notable changes in Python 3.9.1: Notable changes in Python 3 9 1.
Notable changes in Python 3.9.2: Notable changes in Python 3 9 2.

New Features

Dictionary Merge & Update Operators
New String Methods to Remove Prefixes and Suffixes
Type Hinting Generics in Standard Collections
New Parser

New Modules

zoneinfo
graphlib

Improved Modules

ast
asyncio: asyncio<2>.
compileall
concurrent.futures: concurrent futures.
curses: curses<2>.
datetime
distutils: distutils<2>.
fcntl
ftplib
gc: gc<2>.
hashlib: hashlib<2>.
http
IDLE and idlelib: IDLE and idlelib<2>.
imaplib
importlib
inspect: inspect<2>.
ipaddress
math
multiprocessing
nntplib
os: os<2>.
pathlib: pathlib<2>.
pdb
poplib
pprint: pprint<2>.
pydoc
random
signal
smtplib
socket: socket<2>.
time
sys: sys<2>.
tracemalloc
typing: typing<2>.
unicodedata
venv
xml: xml<2>.

Porting to Python 3.9

Changes in the Python API: Changes in the Python API<2>.
Changes in the C API: Changes in the C API<2>.
CPython bytecode changes: CPython bytecode changes<2>.

C API Changes

New Features: New Features<4>.
Porting to Python 3.9: Porting to Python 3 9<2>.
Removed: Removed<4>.

Notable changes in Python 3.9.1

typing: typing<3>.
macOS 11.0 (Big Sur) and Apple Silicon Mac support: macOS 11 0 Big Sur and Apple Silicon Mac support.

Notable changes in Python 3.9.2

collections.abc: collections abc<2>.
urllib.parse: urllib parse<2>.

What’s New In Python 3.8

Summary – Release highlights: Summary – Release highlights<3>.
New Features: New Features<5>.
Other Language Changes: Other Language Changes<3>.
New Modules: New Modules<3>.
Improved Modules: Improved Modules<3>.
Optimizations: Optimizations<3>.
Build and C API Changes
Deprecated: Deprecated<4>.
API and Feature Removals
Porting to Python 3.8: Porting to Python 3 8.
Notable changes in Python 3.8.1: Notable changes in Python 3 8 1.
Notable changes in Python 3.8.8: Notable changes in Python 3 8 8.
Notable changes in Python 3.8.12: Notable changes in Python 3 8 12.

New Features

Assignment expressions
Positional-only parameters
Parallel filesystem cache for compiled bytecode files
Debug build uses the same ABI as release build
f-strings support = for self-documenting expressions and debugging
PEP 578; Python Runtime Audit Hooks: PEP 578 Python Runtime Audit Hooks.
PEP 587; Python Initialization Configuration: PEP 587 Python Initialization Configuration.
PEP 590; Vectorcall; a fast calling protocol for CPython: PEP 590 Vectorcall a fast calling protocol for CPython.
Pickle protocol 5 with out-of-band data buffers

Improved Modules

ast: ast<2>.
asyncio: asyncio<3>.
builtins
collections
cProfile
csv
curses: curses<3>.
ctypes
datetime: datetime<2>.
functools
gc: gc<3>.
gettext
gzip
IDLE and idlelib: IDLE and idlelib<3>.
inspect: inspect<3>.
io
itertools: itertools<2>.
json.tool: json tool.
logging
math: math<2>.
mmap
multiprocessing: multiprocessing<2>.
os: os<3>.
os.path: os path<2>.
pathlib: pathlib<3>.
pickle
plistlib
pprint: pprint<3>.
py_compile: py_compile<2>.
shlex
shutil
socket: socket<3>.
ssl: ssl<2>.
statistics: statistics<2>.
sys: sys<3>.
tarfile: tarfile<2>.
threading: threading<2>.
tokenize
tkinter
time: time<2>.
typing: typing<4>.
unicodedata: unicodedata<2>.
unittest: unittest<2>.
venv: venv<2>.
weakref
xml: xml<3>.
xmlrpc

Porting to Python 3.8

Changes in Python behavior
Changes in the Python API: Changes in the Python API<3>.
Changes in the C API: Changes in the C API<3>.
CPython bytecode changes: CPython bytecode changes<3>.
Demos and Tools

What’s New In Python 3.7

Summary – Release Highlights
New Features: New Features<6>.
Other Language Changes: Other Language Changes<4>.
New Modules: New Modules<4>.
Improved Modules: Improved Modules<4>.
C API Changes: C API Changes<3>.
Build Changes: Build Changes<3>.
Optimizations: Optimizations<4>.
Other CPython Implementation Changes
Deprecated Python Behavior
Deprecated Python modules, functions and methods: Deprecated Python modules functions and methods.
Deprecated functions and types of the C API
Platform Support Removals
API and Feature Removals: API and Feature Removals<2>.
Module Removals
Windows-only Changes
Porting to Python 3.7: Porting to Python 3 7.
Notable changes in Python 3.7.1: Notable changes in Python 3 7 1.
Notable changes in Python 3.7.2: Notable changes in Python 3 7 2.
Notable changes in Python 3.7.6: Notable changes in Python 3 7 6.
Notable changes in Python 3.7.10: Notable changes in Python 3 7 10.

New Features

PEP 563; Postponed Evaluation of Annotations: PEP 563 Postponed Evaluation of Annotations.
PEP 538; Legacy C Locale Coercion: PEP 538 Legacy C Locale Coercion.
PEP 540; Forced UTF-8 Runtime Mode: PEP 540 Forced UTF-8 Runtime Mode.
PEP 553; Built-in breakpoint(): PEP 553 Built-in breakpoint.
PEP 539; New C API for Thread-Local Storage: PEP 539 New C API for Thread-Local Storage.
PEP 562; Customization of Access to Module Attributes: PEP 562 Customization of Access to Module Attributes.
PEP 564; New Time Functions With Nanosecond Resolution: PEP 564 New Time Functions With Nanosecond Resolution.
PEP 565; Show DeprecationWarning in __main__: PEP 565 Show DeprecationWarning in __main__.
PEP 560; Core Support for typing module and Generic Types: PEP 560 Core Support for typing module and Generic Types.
PEP 552; Hash-based .pyc Files: PEP 552 Hash-based pyc Files.
PEP 545; Python Documentation Translations: PEP 545 Python Documentation Translations.
Python Development Mode (-X dev): Python Development Mode -X dev.

New Modules

contextvars
dataclasses: dataclasses<2>.
importlib.resources: importlib resources.

Improved Modules

argparse: argparse<2>.
asyncio: asyncio<4>.
binascii
calendar
collections: collections<2>.
compileall: compileall<2>.
concurrent.futures: concurrent futures<2>.
contextlib: contextlib<2>.
cProfile: cProfile<2>.
crypt
datetime: datetime<3>.
dbm
decimal
dis
distutils: distutils<3>.
enum
functools: functools<2>.
gc: gc<4>.
hmac: hmac<2>.
http.client: http client.
http.server: http server.
idlelib and IDLE
importlib: importlib<2>.
io: io<2>.
ipaddress: ipaddress<2>.
itertools: itertools<3>.
locale
logging: logging<2>.
math: math<3>.
mimetypes
msilib
multiprocessing: multiprocessing<3>.
os: os<4>.
pathlib: pathlib<4>.
pdb: pdb<2>.
py_compile: py_compile<3>.
pydoc: pydoc<2>.
queue
re
signal: signal<2>.
socket: socket<4>.
socketserver
sqlite3: sqlite3<2>.
ssl: ssl<3>.
string
subprocess
sys: sys<4>.
time: time<3>.
tkinter: tkinter<2>.
tracemalloc: tracemalloc<2>.
types: types<2>.
unicodedata: unicodedata<3>.
unittest: unittest<3>.
unittest.mock: unittest mock.
urllib.parse: urllib parse<3>.
uu
uuid
warnings
xml.etree: xml etree.
xmlrpc.server: xmlrpc server.
zipapp
zipfile

Deprecated Python modules, functions and methods

aifc
asyncio: asyncio<5>.
collections: collections<3>.
dbm: dbm<2>.
enum: enum<2>.
gettext: gettext<2>.
importlib: importlib<3>.
locale: locale<2>.
macpath
threading: threading<3>.
socket: socket<5>.
ssl: ssl<4>.
sunau
sys: sys<5>.
wave

Porting to Python 3.7

Changes in Python Behavior
Changes in the Python API: Changes in the Python API<4>.
Changes in the C API: Changes in the C API<4>.
CPython bytecode changes: CPython bytecode changes<4>.
Windows-only Changes: Windows-only Changes<2>.
Other CPython implementation changes

What’s New In Python 3.6

Summary – Release highlights: Summary – Release highlights<4>.
New Features: New Features<7>.
Other Language Changes: Other Language Changes<5>.
New Modules: New Modules<5>.
Improved Modules: Improved Modules<5>.
Optimizations: Optimizations<5>.
Build and C API Changes: Build and C API Changes<2>.
Other Improvements
Deprecated: Deprecated<5>.
Removed: Removed<5>.
Porting to Python 3.6: Porting to Python 3 6.
Notable changes in Python 3.6.2: Notable changes in Python 3 6 2.
Notable changes in Python 3.6.4: Notable changes in Python 3 6 4.
Notable changes in Python 3.6.5: Notable changes in Python 3 6 5.
Notable changes in Python 3.6.7: Notable changes in Python 3 6 7.
Notable changes in Python 3.6.10: Notable changes in Python 3 6 10.
Notable changes in Python 3.6.13: Notable changes in Python 3 6 13.

New Features

PEP 498; Formatted string literals: PEP 498 Formatted string literals.
PEP 526; Syntax for variable annotations: PEP 526 Syntax for variable annotations.
PEP 515; Underscores in Numeric Literals: PEP 515 Underscores in Numeric Literals.
PEP 525; Asynchronous Generators: PEP 525 Asynchronous Generators.
PEP 530; Asynchronous Comprehensions: PEP 530 Asynchronous Comprehensions.
PEP 487; Simpler customization of class creation: PEP 487 Simpler customization of class creation.
PEP 487; Descriptor Protocol Enhancements: PEP 487 Descriptor Protocol Enhancements.
PEP 519; Adding a file system path protocol: PEP 519 Adding a file system path protocol.
PEP 495; Local Time Disambiguation: PEP 495 Local Time Disambiguation.
PEP 529; Change Windows filesystem encoding to UTF-8: PEP 529 Change Windows filesystem encoding to UTF-8.
PEP 528; Change Windows console encoding to UTF-8: PEP 528 Change Windows console encoding to UTF-8.
PEP 520; Preserving Class Attribute Definition Order: PEP 520 Preserving Class Attribute Definition Order.
PEP 468; Preserving Keyword Argument Order: PEP 468 Preserving Keyword Argument Order.
New dict implementation
PEP 523; Adding a frame evaluation API to CPython: PEP 523 Adding a frame evaluation API to CPython.
PYTHONMALLOC environment variable
DTrace and SystemTap probing support

New Modules

secrets

Improved Modules

array: array<2>.
ast: ast<3>.
asyncio: asyncio<6>.
binascii: binascii<2>.
cmath
collections: collections<4>.
concurrent.futures: concurrent futures<3>.
contextlib: contextlib<3>.
datetime: datetime<4>.
decimal: decimal<2>.
distutils: distutils<4>.
email
encodings: encodings<2>.
enum: enum<3>.
faulthandler: faulthandler<2>.
fileinput: fileinput<2>.
hashlib: hashlib<3>.
http.client: http client<2>.
idlelib and IDLE: idlelib and IDLE<2>.
importlib: importlib<4>.
inspect: inspect<4>.
json
logging: logging<3>.
math: math<4>.
multiprocessing: multiprocessing<4>.
os: os<5>.
pathlib: pathlib<5>.
pdb: pdb<3>.
pickle: pickle<2>.
pickletools
pydoc: pydoc<3>.
random: random<2>.
re: re<2>.
readline
rlcompleter
shlex: shlex<2>.
site: site<2>.
sqlite3: sqlite3<3>.
socket: socket<6>.
socketserver: socketserver<2>.
ssl: ssl<5>.
statistics: statistics<3>.
struct
subprocess: subprocess<2>.
sys: sys<6>.
telnetlib
time: time<4>.
timeit
tkinter: tkinter<3>.
traceback: traceback<2>.
tracemalloc: tracemalloc<3>.
typing: typing<5>.
unicodedata: unicodedata<4>.
unittest.mock: unittest mock<2>.
urllib.request: urllib request.
urllib.robotparser: urllib robotparser.
venv: venv<3>.
warnings: warnings<2>.
winreg
winsound
xmlrpc.client: xmlrpc client.
zipfile: zipfile<2>.
zlib

Deprecated

New Keywords
Deprecated Python behavior
Deprecated Python modules, functions and methods: Deprecated Python modules functions and methods<2>.
Deprecated functions and types of the C API: Deprecated functions and types of the C API<2>.
Deprecated Build Options

Deprecated Python modules, functions and methods

asynchat
asyncore
dbm: dbm<3>.
distutils: distutils<5>.
grp
importlib: importlib<5>.
os: os<6>.
re: re<3>.
ssl: ssl<6>.
tkinter: tkinter<4>.
venv: venv<4>.

Removed

API and Feature Removals: API and Feature Removals<3>.

Porting to Python 3.6

Changes in ‘python’ Command Behavior
Changes in the Python API: Changes in the Python API<5>.
Changes in the C API: Changes in the C API<5>.
CPython bytecode changes: CPython bytecode changes<5>.

Notable changes in Python 3.6.2

New make regen-all build target
Removal of make touch build target

What’s New In Python 3.5

Summary – Release highlights: Summary – Release highlights<5>.
New Features: New Features<8>.
Other Language Changes: Other Language Changes<6>.
New Modules: New Modules<6>.
Improved Modules: Improved Modules<6>.
Other module-level changes
Optimizations: Optimizations<6>.
Build and C API Changes: Build and C API Changes<3>.
Deprecated: Deprecated<6>.
Removed: Removed<6>.
Porting to Python 3.5: Porting to Python 3 5.
Notable changes in Python 3.5.4: Notable changes in Python 3 5 4.

New Features

PEP 492 - Coroutines with async and await syntax
PEP 465 - A dedicated infix operator for matrix multiplication
PEP 448 - Additional Unpacking Generalizations
PEP 461 - percent formatting support for bytes and bytearray
PEP 484 - Type Hints
PEP 471 - os.scandir() function – a better and faster directory iterator: PEP 471 - os scandir function – a better and faster directory iterator.
PEP 475; Retry system calls failing with EINTR: PEP 475 Retry system calls failing with EINTR.
PEP 479; Change StopIteration handling inside generators: PEP 479 Change StopIteration handling inside generators.
PEP 485; A function for testing approximate equality: PEP 485 A function for testing approximate equality.
PEP 486; Make the Python Launcher aware of virtual environments: PEP 486 Make the Python Launcher aware of virtual environments.
PEP 488; Elimination of PYO files: PEP 488 Elimination of PYO files.
PEP 489; Multi-phase extension module initialization: PEP 489 Multi-phase extension module initialization.

New Modules

typing: typing<6>.
zipapp: zipapp<2>.

Improved Modules

argparse: argparse<3>.
asyncio: asyncio<7>.
bz2
cgi
cmath: cmath<2>.
code
collections: collections<5>.
collections.abc: collections abc<3>.
compileall: compileall<3>.
concurrent.futures: concurrent futures<4>.
configparser
contextlib: contextlib<4>.
csv: csv<2>.
curses: curses<4>.
dbm: dbm<4>.
difflib
distutils: distutils<6>.
doctest: doctest<2>.
email: email<2>.
enum: enum<4>.
faulthandler: faulthandler<3>.
functools: functools<3>.
glob: glob<2>.
gzip: gzip<2>.
heapq
http: http<2>.
http.client: http client<3>.
idlelib and IDLE: idlelib and IDLE<3>.
imaplib: imaplib<2>.
imghdr
importlib: importlib<6>.
inspect: inspect<5>.
io: io<3>.
ipaddress: ipaddress<3>.
json: json<2>.
linecache: linecache<2>.
locale: locale<3>.
logging: logging<4>.
lzma
math: math<5>.
multiprocessing: multiprocessing<5>.
operator
os: os<7>.
pathlib: pathlib<6>.
pickle: pickle<3>.
poplib: poplib<2>.
re: re<4>.
readline: readline<2>.
selectors
shutil: shutil<2>.
signal: signal<3>.
smtpd
smtplib: smtplib<2>.
sndhdr
socket: socket<7>.
ssl: ssl<7>.
sqlite3: sqlite3<4>.
subprocess: subprocess<3>.
sys: sys<7>.
sysconfig
tarfile: tarfile<3>.
threading: threading<4>.
time: time<5>.
timeit: timeit<2>.
tkinter: tkinter<5>.
traceback: traceback<3>.
types: types<3>.
unicodedata: unicodedata<5>.
unittest: unittest<4>.
unittest.mock: unittest mock<3>.
urllib
wsgiref
xmlrpc: xmlrpc<2>.
xml.sax: xml sax.
zipfile: zipfile<3>.

ssl

Memory BIO Support
Application-Layer Protocol Negotiation Support
Other Changes

Deprecated

New Keywords: New Keywords<2>.
Deprecated Python Behavior: Deprecated Python Behavior<2>.
Unsupported Operating Systems
Deprecated Python modules, functions and methods: Deprecated Python modules functions and methods<3>.

Removed

API and Feature Removals: API and Feature Removals<4>.

Porting to Python 3.5

Changes in Python behavior: Changes in Python behavior<2>.
Changes in the Python API: Changes in the Python API<6>.
Changes in the C API: Changes in the C API<6>.

Notable changes in Python 3.5.4

New make regen-all build target: New make regen-all build target<2>.
Removal of make touch build target: Removal of make touch build target<2>.

What’s New In Python 3.4

Summary – Release Highlights: Summary – Release Highlights<2>.
New Features: New Features<9>.
New Modules: New Modules<7>.
Improved Modules: Improved Modules<7>.
CPython Implementation Changes
Deprecated: Deprecated<7>.
Removed: Removed<7>.
Porting to Python 3.4: Porting to Python 3 4.
Changed in 3.4.3: Changed in 3 4 3.

New Features

PEP 453; Explicit Bootstrapping of PIP in Python Installations: PEP 453 Explicit Bootstrapping of PIP in Python Installations.
PEP 446; Newly Created File Descriptors Are Non-Inheritable: PEP 446 Newly Created File Descriptors Are Non-Inheritable.
Improvements to Codec Handling
PEP 451; A ModuleSpec Type for the Import System: PEP 451 A ModuleSpec Type for the Import System.
Other Language Changes: Other Language Changes<7>.

PEP 453: Explicit Bootstrapping of PIP in Python Installations

Bootstrapping pip By Default
Documentation Changes

New Modules

asyncio: asyncio<8>.
ensurepip
enum: enum<5>.
pathlib: pathlib<7>.
selectors: selectors<2>.
statistics: statistics<4>.
tracemalloc: tracemalloc<4>.

Improved Modules

abc
aifc: aifc<2>.
argparse: argparse<4>.
audioop
base64: base64<2>.
collections: collections<6>.
colorsys
contextlib: contextlib<5>.
dbm: dbm<5>.
dis: dis<2>.
doctest: doctest<3>.
email: email<3>.
filecmp
functools: functools<4>.
gc: gc<5>.
glob: glob<3>.
hashlib: hashlib<4>.
hmac: hmac<3>.
html
http: http<3>.
idlelib and IDLE: idlelib and IDLE<4>.
importlib: importlib<7>.
inspect: inspect<6>.
ipaddress: ipaddress<4>.
logging: logging<5>.
marshal
mmap: mmap<2>.
multiprocessing: multiprocessing<6>.
operator: operator<2>.
os: os<8>.
pdb: pdb<4>.
pickle: pickle<4>.
plistlib: plistlib<2>.
poplib: poplib<3>.
pprint: pprint<4>.
pty
pydoc: pydoc<4>.
re: re<5>.
resource
select
shelve: shelve<2>.
shutil: shutil<3>.
smtpd: smtpd<2>.
smtplib: smtplib<3>.
socket: socket<8>.
sqlite3: sqlite3<5>.
ssl: ssl<8>.
stat
struct: struct<2>.
subprocess: subprocess<4>.
sunau: sunau<2>.
sys: sys<8>.
tarfile: tarfile<4>.
textwrap
threading: threading<5>.
traceback: traceback<4>.
types: types<4>.
urllib: urllib<2>.
unittest: unittest<5>.
venv: venv<5>.
wave: wave<2>.
weakref: weakref<2>.
xml.etree: xml etree<2>.
zipfile: zipfile<4>.

CPython Implementation Changes

PEP 445; Customization of CPython Memory Allocators: PEP 445 Customization of CPython Memory Allocators.
PEP 442; Safe Object Finalization: PEP 442 Safe Object Finalization.
PEP 456; Secure and Interchangeable Hash Algorithm: PEP 456 Secure and Interchangeable Hash Algorithm.
PEP 436; Argument Clinic: PEP 436 Argument Clinic.
Other Build and C API Changes
Other Improvements: Other Improvements<2>.
Significant Optimizations

Deprecated

Deprecations in the Python API
Deprecated Features

Removed

Operating Systems No Longer Supported
API and Feature Removals: API and Feature Removals<5>.
Code Cleanups

Porting to Python 3.4

Changes in ‘python’ Command Behavior: Changes in ‘python’ Command Behavior<2>.
Changes in the Python API: Changes in the Python API<7>.
Changes in the C API: Changes in the C API<7>.

Changed in 3.4.3

PEP 476; Enabling certificate verification by default for stdlib http clients: PEP 476 Enabling certificate verification by default for stdlib http clients.

What’s New In Python 3.3

Summary – Release highlights: Summary – Release highlights<6>.
PEP 405; Virtual Environments: PEP 405 Virtual Environments.
PEP 420; Implicit Namespace Packages: PEP 420 Implicit Namespace Packages.
PEP 3118; New memoryview implementation and buffer protocol documentation: PEP 3118 New memoryview implementation and buffer protocol documentation.
PEP 393; Flexible String Representation: PEP 393 Flexible String Representation.
PEP 397; Python Launcher for Windows: PEP 397 Python Launcher for Windows.
PEP 3151; Reworking the OS and IO exception hierarchy: PEP 3151 Reworking the OS and IO exception hierarchy.
PEP 380; Syntax for Delegating to a Subgenerator: PEP 380 Syntax for Delegating to a Subgenerator.
PEP 409; Suppressing exception context: PEP 409 Suppressing exception context.
PEP 414; Explicit Unicode literals: PEP 414 Explicit Unicode literals.
PEP 3155; Qualified name for classes and functions: PEP 3155 Qualified name for classes and functions.
PEP 412; Key-Sharing Dictionary: PEP 412 Key-Sharing Dictionary.
PEP 362; Function Signature Object: PEP 362 Function Signature Object.
PEP 421; Adding sys.implementation: PEP 421 Adding sys implementation.
Using importlib as the Implementation of Import
Other Language Changes: Other Language Changes<8>.
A Finer-Grained Import Lock
Builtin functions and types
New Modules: New Modules<8>.
Improved Modules: Improved Modules<8>.
Optimizations: Optimizations<7>.
Build and C API Changes: Build and C API Changes<4>.
Deprecated: Deprecated<8>.
Porting to Python 3.3: Porting to Python 3 3.

PEP 3118: New memoryview implementation and buffer protocol documentation

Features
API changes

PEP 393: Flexible String Representation

Functionality
Performance and resource usage

PEP 421: Adding sys.implementation

SimpleNamespace

Using importlib as the Implementation of Import

New APIs
Visible Changes

New Modules

faulthandler: faulthandler<4>.
ipaddress: ipaddress<5>.
lzma: lzma<2>.

Improved Modules

abc: abc<2>.
array: array<3>.
base64: base64<3>.
binascii: binascii<3>.
bz2: bz2<2>.
codecs: codecs<2>.
collections: collections<7>.
contextlib: contextlib<6>.
crypt: crypt<2>.
curses: curses<5>.
datetime: datetime<5>.
decimal: decimal<3>.
email: email<4>.
ftplib: ftplib<2>.
functools: functools<5>.
gc: gc<6>.
hmac: hmac<4>.
http: http<4>.
html: html<2>.
imaplib: imaplib<3>.
inspect: inspect<7>.
io: io<4>.
itertools: itertools<4>.
logging: logging<6>.
math: math<6>.
mmap: mmap<3>.
multiprocessing: multiprocessing<7>.
nntplib: nntplib<2>.
os: os<9>.
pdb: pdb<5>.
pickle: pickle<5>.
pydoc: pydoc<5>.
re: re<6>.
sched
select: select<2>.
shlex: shlex<3>.
shutil: shutil<4>.
signal: signal<4>.
smtpd: smtpd<3>.
smtplib: smtplib<4>.
socket: socket<9>.
socketserver: socketserver<3>.
sqlite3: sqlite3<6>.
ssl: ssl<9>.
stat: stat<2>.
struct: struct<3>.
subprocess: subprocess<5>.
sys: sys<9>.
tarfile: tarfile<5>.
tempfile
textwrap: textwrap<2>.
threading: threading<6>.
time: time<6>.
types: types<5>.
unittest: unittest<6>.
urllib: urllib<3>.
webbrowser
xml.etree.ElementTree: xml etree ElementTree.
zlib: zlib<2>.

decimal

Features: Features<2>.
API changes: API changes<2>.

email

Policy Framework
Provisional Policy with New Header API
Other API Changes

Deprecated

Unsupported Operating Systems: Unsupported Operating Systems<2>.
Deprecated Python modules, functions and methods: Deprecated Python modules functions and methods<4>.
Deprecated functions and types of the C API: Deprecated functions and types of the C API<3>.
Deprecated features

Porting to Python 3.3

Porting Python code
Porting C code
Building C extensions
Command Line Switch Changes

What’s New In Python 3.2

PEP 384; Defining a Stable ABI: PEP 384 Defining a Stable ABI.
PEP 389; Argparse Command Line Parsing Module: PEP 389 Argparse Command Line Parsing Module.
PEP 391; Dictionary Based Configuration for Logging: PEP 391 Dictionary Based Configuration for Logging.
PEP 3148; The concurrent.futures module: PEP 3148 The concurrent futures module.
PEP 3147; PYC Repository Directories: PEP 3147 PYC Repository Directories.
PEP 3149; ABI Version Tagged .so Files: PEP 3149 ABI Version Tagged so Files.
PEP 3333; Python Web Server Gateway Interface v1.0.1: PEP 3333 Python Web Server Gateway Interface v1 0 1.
Other Language Changes: Other Language Changes<9>.
New, Improved, and Deprecated Modules: New Improved and Deprecated Modules.
Multi-threading
Optimizations: Optimizations<8>.
Unicode
Codecs
Documentation
IDLE
Code Repository
Build and C API Changes: Build and C API Changes<5>.
Porting to Python 3.2: Porting to Python 3 2.

New, Improved, and Deprecated Modules

email: email<5>.
elementtree
functools: functools<6>.
itertools: itertools<5>.
collections: collections<8>.
threading: threading<7>.
datetime and time
math: math<7>.
abc: abc<3>.
io: io<5>.
reprlib
logging: logging<7>.
csv: csv<3>.
contextlib: contextlib<7>.
decimal and fractions
ftp
popen
select: select<3>.
gzip and zipfile
tarfile: tarfile<6>.
hashlib: hashlib<5>.
ast: ast<4>.
os: os<10>.
shutil: shutil<5>.
sqlite3: sqlite3<7>.
html: html<3>.
socket: socket<10>.
ssl: ssl<10>.
nntp
certificates
imaplib: imaplib<4>.
http.client: http client<4>.
unittest: unittest<7>.
random: random<3>.
poplib: poplib<4>.
asyncore: asyncore<2>.
tempfile: tempfile<2>.
inspect: inspect<8>.
pydoc: pydoc<6>.
dis: dis<3>.
dbm: dbm<6>.
ctypes: ctypes<2>.
site: site<3>.
sysconfig: sysconfig<2>.
pdb: pdb<6>.
configparser: configparser<2>.
urllib.parse: urllib parse<4>.
mailbox
turtledemo

What’s New In Python 3.1

PEP 372; Ordered Dictionaries: PEP 372 Ordered Dictionaries.
PEP 378; Format Specifier for Thousands Separator: PEP 378 Format Specifier for Thousands Separator.
Other Language Changes: Other Language Changes<10>.
New, Improved, and Deprecated Modules: New Improved and Deprecated Modules<2>.
Optimizations: Optimizations<9>.
IDLE: IDLE<2>.
Build and C API Changes: Build and C API Changes<6>.
Porting to Python 3.1: Porting to Python 3 1.

What’s New In Python 3.0

Common Stumbling Blocks
Overview Of Syntax Changes
Changes Already Present In Python 2.6: Changes Already Present In Python 2 6.
Library Changes
PEP 3101; A New Approach To String Formatting: PEP 3101 A New Approach To String Formatting.
Changes To Exceptions
Miscellaneous Other Changes
Build and C API Changes: Build and C API Changes<7>.
Performance
Porting To Python 3.0: Porting To Python 3 0.

Common Stumbling Blocks

Print Is A Function
Views And Iterators Instead Of Lists
Ordering Comparisons
Integers
Text Vs. Data Instead Of Unicode Vs. 8-bit: Text Vs Data Instead Of Unicode Vs 8-bit.

Overview Of Syntax Changes

New Syntax
Changed Syntax
Removed Syntax

Miscellaneous Other Changes

Operators And Special Methods
Builtins

What’s New in Python 2.7

The Future for Python 2.x: The Future for Python 2 x.
Changes to the Handling of Deprecation Warnings
Python 3.1 Features: Python 3 1 Features.
PEP 372; Adding an Ordered Dictionary to collections: PEP 372 Adding an Ordered Dictionary to collections.
PEP 378; Format Specifier for Thousands Separator: PEP 378 Format Specifier for Thousands Separator<2>.
PEP 389; The argparse Module for Parsing Command Lines: PEP 389 The argparse Module for Parsing Command Lines.
PEP 391; Dictionary-Based Configuration For Logging: PEP 391 Dictionary-Based Configuration For Logging.
PEP 3106; Dictionary Views: PEP 3106 Dictionary Views.
PEP 3137; The memoryview Object: PEP 3137 The memoryview Object.
Other Language Changes: Other Language Changes<11>.
New and Improved Modules
Build and C API Changes: Build and C API Changes<8>.
Other Changes and Fixes
Porting to Python 2.7: Porting to Python 2 7.
New Features Added to Python 2.7 Maintenance Releases: New Features Added to Python 2 7 Maintenance Releases.
Acknowledgements

Other Language Changes

Interpreter Changes
Optimizations: Optimizations<10>.

New and Improved Modules

New module; importlib: New module importlib.
New module; sysconfig: New module sysconfig.
ttk; Themed Widgets for Tk: ttk Themed Widgets for Tk.
Updated module; unittest: Updated module unittest.
Updated module; ElementTree 1.3: Updated module ElementTree 1 3.

Build and C API Changes

Capsules
Port-Specific Changes; Windows: Port-Specific Changes Windows.
Port-Specific Changes; Mac OS X: Port-Specific Changes Mac OS X.
Port-Specific Changes; FreeBSD: Port-Specific Changes FreeBSD.

New Features Added to Python 2.7 Maintenance Releases

Two new environment variables for debug mode
PEP 434; IDLE Enhancement Exception for All Branches: PEP 434 IDLE Enhancement Exception for All Branches.
PEP 466; Network Security Enhancements for Python 2.7: PEP 466 Network Security Enhancements for Python 2 7.
PEP 477; Backport ensurepip (PEP 453) to Python 2.7: PEP 477 Backport ensurepip PEP 453 to Python 2 7.
PEP 476; Enabling certificate verification by default for stdlib http clients: PEP 476 Enabling certificate verification by default for stdlib http clients<2>.
PEP 493; HTTPS verification migration tools for Python 2.7: PEP 493 HTTPS verification migration tools for Python 2 7.
New make regen-all build target: New make regen-all build target<3>.
Removal of make touch build target: Removal of make touch build target<3>.

PEP 477: Backport ensurepip (PEP 453) to Python 2.7

Bootstrapping pip By Default: Bootstrapping pip By Default<2>.
Documentation Changes: Documentation Changes<2>.

What’s New in Python 2.6

Python 3.0: Python 3 0.
Changes to the Development Process
PEP 343; The ‘with’ statement: PEP 343 The ‘with’ statement.
PEP 366; Explicit Relative Imports From a Main Module: PEP 366 Explicit Relative Imports From a Main Module.
PEP 370; Per-user site-packages Directory: PEP 370 Per-user site-packages Directory.
PEP 371; The multiprocessing Package: PEP 371 The multiprocessing Package.
PEP 3101; Advanced String Formatting: PEP 3101 Advanced String Formatting.
PEP 3105; print As a Function: PEP 3105 print As a Function.
PEP 3110; Exception-Handling Changes: PEP 3110 Exception-Handling Changes.
PEP 3112; Byte Literals: PEP 3112 Byte Literals.
PEP 3116; New I/O Library: PEP 3116 New I/O Library.
PEP 3118; Revised Buffer Protocol: PEP 3118 Revised Buffer Protocol.
PEP 3119; Abstract Base Classes: PEP 3119 Abstract Base Classes.
PEP 3127; Integer Literal Support and Syntax: PEP 3127 Integer Literal Support and Syntax.
PEP 3129; Class Decorators: PEP 3129 Class Decorators.
PEP 3141; A Type Hierarchy for Numbers: PEP 3141 A Type Hierarchy for Numbers.
Other Language Changes: Other Language Changes<12>.
New and Improved Modules: New and Improved Modules<2>.
Deprecations and Removals
Build and C API Changes: Build and C API Changes<9>.
Porting to Python 2.6: Porting to Python 2 6.
Acknowledgements: Acknowledgements<2>.

Changes to the Development Process

New Issue Tracker; Roundup: New Issue Tracker Roundup.
New Documentation Format; reStructuredText Using Sphinx: New Documentation Format reStructuredText Using Sphinx.

PEP 343: The ‘with’ statement

Writing Context Managers
The contextlib module

PEP 3141: A Type Hierarchy for Numbers

The fractions Module

Other Language Changes

Optimizations: Optimizations<11>.
Interpreter Changes: Interpreter Changes<2>.

New and Improved Modules

The ast module
The future_builtins module
The json module; JavaScript Object Notation: The json module JavaScript Object Notation.
The plistlib module; A Property-List Parser: The plistlib module A Property-List Parser.
ctypes Enhancements
Improved SSL Support

Build and C API Changes

Port-Specific Changes; Windows: Port-Specific Changes Windows<2>.
Port-Specific Changes; Mac OS X: Port-Specific Changes Mac OS X<2>.
Port-Specific Changes; IRIX: Port-Specific Changes IRIX.

What’s New in Python 2.5

PEP 308; Conditional Expressions: PEP 308 Conditional Expressions.
PEP 309; Partial Function Application: PEP 309 Partial Function Application.
PEP 314; Metadata for Python Software Packages v1.1: PEP 314 Metadata for Python Software Packages v1 1.
PEP 328; Absolute and Relative Imports: PEP 328 Absolute and Relative Imports.
PEP 338; Executing Modules as Scripts: PEP 338 Executing Modules as Scripts.
PEP 341; Unified try/except/finally: PEP 341 Unified try/except/finally.
PEP 342; New Generator Features: PEP 342 New Generator Features.
PEP 343; The ‘with’ statement: PEP 343 The ‘with’ statement<2>.
PEP 352; Exceptions as New-Style Classes: PEP 352 Exceptions as New-Style Classes.
PEP 353; Using ssize_t as the index type: PEP 353 Using ssize_t as the index type.
PEP 357; The ‘__index__’ method: PEP 357 The ‘__index__’ method.
Other Language Changes: Other Language Changes<13>.
New, Improved, and Removed Modules: New Improved and Removed Modules.
Build and C API Changes: Build and C API Changes<10>.
Porting to Python 2.5: Porting to Python 2 5.
Acknowledgements: Acknowledgements<3>.

PEP 343: The ‘with’ statement

Writing Context Managers: Writing Context Managers<2>.
The contextlib module: The contextlib module<2>.

Other Language Changes

Interactive Interpreter Changes
Optimizations: Optimizations<12>.

New, Improved, and Removed Modules

The ctypes package
The ElementTree package
The hashlib package
The sqlite3 package
The wsgiref package

Build and C API Changes

Port-Specific Changes

What’s New in Python 2.4

PEP 218; Built-In Set Objects: PEP 218 Built-In Set Objects.
PEP 237; Unifying Long Integers and Integers: PEP 237 Unifying Long Integers and Integers.
PEP 289; Generator Expressions: PEP 289 Generator Expressions.
PEP 292; Simpler String Substitutions: PEP 292 Simpler String Substitutions.
PEP 318; Decorators for Functions and Methods: PEP 318 Decorators for Functions and Methods.
PEP 322; Reverse Iteration: PEP 322 Reverse Iteration.
PEP 324; New subprocess Module: PEP 324 New subprocess Module.
PEP 327; Decimal Data Type: PEP 327 Decimal Data Type.
PEP 328; Multi-line Imports: PEP 328 Multi-line Imports.
PEP 331; Locale-Independent Float/String Conversions: PEP 331 Locale-Independent Float/String Conversions.
Other Language Changes: Other Language Changes<14>.
New, Improved, and Deprecated Modules: New Improved and Deprecated Modules<3>.
Build and C API Changes: Build and C API Changes<11>.
Porting to Python 2.4: Porting to Python 2 4.
Acknowledgements: Acknowledgements<4>.

PEP 327: Decimal Data Type

Why is Decimal needed?
The Decimal type
The Context type

Other Language Changes

Optimizations: Optimizations<13>.

New, Improved, and Deprecated Modules

cookielib
doctest: doctest<4>.

Build and C API Changes

Port-Specific Changes: Port-Specific Changes<2>.

What’s New in Python 2.3

PEP 218; A Standard Set Datatype: PEP 218 A Standard Set Datatype.
PEP 255; Simple Generators: PEP 255 Simple Generators.
PEP 263; Source Code Encodings: PEP 263 Source Code Encodings.
PEP 273; Importing Modules from ZIP Archives: PEP 273 Importing Modules from ZIP Archives.
PEP 277; Unicode file name support for Windows NT: PEP 277 Unicode file name support for Windows NT.
PEP 278; Universal Newline Support: PEP 278 Universal Newline Support.
PEP 279; enumerate(): PEP 279 enumerate.
PEP 282; The logging Package: PEP 282 The logging Package.
PEP 285; A Boolean Type: PEP 285 A Boolean Type.
PEP 293; Codec Error Handling Callbacks: PEP 293 Codec Error Handling Callbacks.
PEP 301; Package Index and Metadata for Distutils: PEP 301 Package Index and Metadata for Distutils.
PEP 302; New Import Hooks: PEP 302 New Import Hooks.
PEP 305; Comma-separated Files: PEP 305 Comma-separated Files.
PEP 307; Pickle Enhancements: PEP 307 Pickle Enhancements.
Extended Slices
Other Language Changes: Other Language Changes<15>.
New, Improved, and Deprecated Modules: New Improved and Deprecated Modules<4>.
Pymalloc; A Specialized Object Allocator: Pymalloc A Specialized Object Allocator.
Build and C API Changes: Build and C API Changes<12>.
Other Changes and Fixes: Other Changes and Fixes<2>.
Porting to Python 2.3: Porting to Python 2 3.
Acknowledgements: Acknowledgements<5>.

Other Language Changes

String Changes
Optimizations: Optimizations<14>.

New, Improved, and Deprecated Modules

Date/Time Type
The optparse Module

Build and C API Changes

Port-Specific Changes: Port-Specific Changes<3>.

What’s New in Python 2.2

Introduction
PEPs 252 and 253; Type and Class Changes: PEPs 252 and 253 Type and Class Changes.
PEP 234; Iterators: PEP 234 Iterators.
PEP 255; Simple Generators: PEP 255 Simple Generators<2>.
PEP 237; Unifying Long Integers and Integers: PEP 237 Unifying Long Integers and Integers<2>.
PEP 238; Changing the Division Operator: PEP 238 Changing the Division Operator.
Unicode Changes
PEP 227; Nested Scopes: PEP 227 Nested Scopes.
New and Improved Modules: New and Improved Modules<3>.
Interpreter Changes and Fixes
Other Changes and Fixes: Other Changes and Fixes<3>.
Acknowledgements: Acknowledgements<6>.

PEPs 252 and 253: Type and Class Changes

Old and New Classes
Descriptors
Multiple Inheritance; The Diamond Rule: Multiple Inheritance The Diamond Rule.
Attribute Access
Related Links

What’s New in Python 2.1

Introduction: Introduction<2>.
PEP 227; Nested Scopes: PEP 227 Nested Scopes<2>.
PEP 236; __future__ Directives: PEP 236 __future__ Directives.
PEP 207; Rich Comparisons: PEP 207 Rich Comparisons.
PEP 230; Warning Framework: PEP 230 Warning Framework.
PEP 229; New Build System: PEP 229 New Build System.
PEP 205; Weak References: PEP 205 Weak References.
PEP 232; Function Attributes: PEP 232 Function Attributes.
PEP 235; Importing Modules on Case-Insensitive Platforms: PEP 235 Importing Modules on Case-Insensitive Platforms.
PEP 217; Interactive Display Hook: PEP 217 Interactive Display Hook.
PEP 208; New Coercion Model: PEP 208 New Coercion Model.
PEP 241; Metadata in Python Packages: PEP 241 Metadata in Python Packages.
New and Improved Modules: New and Improved Modules<4>.
Other Changes and Fixes: Other Changes and Fixes<4>.
Acknowledgements: Acknowledgements<7>.

What’s New in Python 2.0

Introduction: Introduction<3>.
What About Python 1.6?: What About Python 1 6?.
New Development Process
Unicode: Unicode<2>.
List Comprehensions
Augmented Assignment
String Methods
Garbage Collection of Cycles
Other Core Changes
Porting to 2.0: Porting to 2 0.
Extending/Embedding Changes
Distutils; Making Modules Easy to Install: Distutils Making Modules Easy to Install.
XML Modules
Module changes
New modules
IDLE Improvements
Deleted and Deprecated Modules
Acknowledgements: Acknowledgements<8>.

Other Core Changes

Minor Language Changes
Changes to Built-in Functions

XML Modules

SAX2 Support
DOM Support
Relationship to PyXML

Changelog

Python 3.10.12 final: Python 3 10 12 final.
Python 3.10.11 final: Python 3 10 11 final.
Python 3.10.10 final: Python 3 10 10 final.
Python 3.10.9 final: Python 3 10 9 final.
Python 3.10.8 final: Python 3 10 8 final.
Python 3.10.7 final: Python 3 10 7 final.
Python 3.10.6 final: Python 3 10 6 final.
Python 3.10.5 final: Python 3 10 5 final.
Python 3.10.4 final: Python 3 10 4 final.
Python 3.10.3 final: Python 3 10 3 final.
Python 3.10.2 final: Python 3 10 2 final.
Python 3.10.1 final: Python 3 10 1 final.
Python 3.10.0 final: Python 3 10 0 final.
Python 3.10.0 release candidate 2: Python 3 10 0 release candidate 2.
Python 3.10.0 release candidate 1: Python 3 10 0 release candidate 1.
Python 3.10.0 beta 4: Python 3 10 0 beta 4.
Python 3.10.0 beta 3: Python 3 10 0 beta 3.
Python 3.10.0 beta 2: Python 3 10 0 beta 2.
Python 3.10.0 beta 1: Python 3 10 0 beta 1.
Python 3.10.0 alpha 7: Python 3 10 0 alpha 7.
Python 3.10.0 alpha 6: Python 3 10 0 alpha 6.
Python 3.10.0 alpha 5: Python 3 10 0 alpha 5.
Python 3.10.0 alpha 4: Python 3 10 0 alpha 4.
Python 3.10.0 alpha 3: Python 3 10 0 alpha 3.
Python 3.10.0 alpha 2: Python 3 10 0 alpha 2.
Python 3.10.0 alpha 1: Python 3 10 0 alpha 1.
Python 3.9.0 beta 1: Python 3 9 0 beta 1.
Python 3.9.0 alpha 6: Python 3 9 0 alpha 6.
Python 3.9.0 alpha 5: Python 3 9 0 alpha 5.
Python 3.9.0 alpha 4: Python 3 9 0 alpha 4.
Python 3.9.0 alpha 3: Python 3 9 0 alpha 3.
Python 3.9.0 alpha 2: Python 3 9 0 alpha 2.
Python 3.9.0 alpha 1: Python 3 9 0 alpha 1.
Python 3.8.0 beta 1: Python 3 8 0 beta 1.
Python 3.8.0 alpha 4: Python 3 8 0 alpha 4.
Python 3.8.0 alpha 3: Python 3 8 0 alpha 3.
Python 3.8.0 alpha 2: Python 3 8 0 alpha 2.
Python 3.8.0 alpha 1: Python 3 8 0 alpha 1.
Python 3.7.0 final: Python 3 7 0 final.
Python 3.7.0 release candidate 1: Python 3 7 0 release candidate 1.
Python 3.7.0 beta 5: Python 3 7 0 beta 5.
Python 3.7.0 beta 4: Python 3 7 0 beta 4.
Python 3.7.0 beta 3: Python 3 7 0 beta 3.
Python 3.7.0 beta 2: Python 3 7 0 beta 2.
Python 3.7.0 beta 1: Python 3 7 0 beta 1.
Python 3.7.0 alpha 4: Python 3 7 0 alpha 4.
Python 3.7.0 alpha 3: Python 3 7 0 alpha 3.
Python 3.7.0 alpha 2: Python 3 7 0 alpha 2.
Python 3.7.0 alpha 1: Python 3 7 0 alpha 1.
Python 3.6.6 final: Python 3 6 6 final.
Python 3.6.6 release candidate 1: Python 3 6 6 release candidate 1.
Python 3.6.5 final: Python 3 6 5 final.
Python 3.6.5 release candidate 1: Python 3 6 5 release candidate 1.
Python 3.6.4 final: Python 3 6 4 final.
Python 3.6.4 release candidate 1: Python 3 6 4 release candidate 1.
Python 3.6.3 final: Python 3 6 3 final.
Python 3.6.3 release candidate 1: Python 3 6 3 release candidate 1.
Python 3.6.2 final: Python 3 6 2 final.
Python 3.6.2 release candidate 2: Python 3 6 2 release candidate 2.
Python 3.6.2 release candidate 1: Python 3 6 2 release candidate 1.
Python 3.6.1 final: Python 3 6 1 final.
Python 3.6.1 release candidate 1: Python 3 6 1 release candidate 1.
Python 3.6.0 final: Python 3 6 0 final.
Python 3.6.0 release candidate 2: Python 3 6 0 release candidate 2.
Python 3.6.0 release candidate 1: Python 3 6 0 release candidate 1.
Python 3.6.0 beta 4: Python 3 6 0 beta 4.
Python 3.6.0 beta 3: Python 3 6 0 beta 3.
Python 3.6.0 beta 2: Python 3 6 0 beta 2.
Python 3.6.0 beta 1: Python 3 6 0 beta 1.
Python 3.6.0 alpha 4: Python 3 6 0 alpha 4.
Python 3.6.0 alpha 3: Python 3 6 0 alpha 3.
Python 3.6.0 alpha 2: Python 3 6 0 alpha 2.
Python 3.6.0 alpha 1: Python 3 6 0 alpha 1.
Python 3.5.5 final: Python 3 5 5 final.
Python 3.5.5 release candidate 1: Python 3 5 5 release candidate 1.
Python 3.5.4 final: Python 3 5 4 final.
Python 3.5.4 release candidate 1: Python 3 5 4 release candidate 1.
Python 3.5.3 final: Python 3 5 3 final.
Python 3.5.3 release candidate 1: Python 3 5 3 release candidate 1.
Python 3.5.2 final: Python 3 5 2 final.
Python 3.5.2 release candidate 1: Python 3 5 2 release candidate 1.
Python 3.5.1 final: Python 3 5 1 final.
Python 3.5.1 release candidate 1: Python 3 5 1 release candidate 1.
Python 3.5.0 final: Python 3 5 0 final.
Python 3.5.0 release candidate 4: Python 3 5 0 release candidate 4.
Python 3.5.0 release candidate 3: Python 3 5 0 release candidate 3.
Python 3.5.0 release candidate 2: Python 3 5 0 release candidate 2.
Python 3.5.0 release candidate 1: Python 3 5 0 release candidate 1.
Python 3.5.0 beta 4: Python 3 5 0 beta 4.
Python 3.5.0 beta 3: Python 3 5 0 beta 3.
Python 3.5.0 beta 2: Python 3 5 0 beta 2.
Python 3.5.0 beta 1: Python 3 5 0 beta 1.
Python 3.5.0 alpha 4: Python 3 5 0 alpha 4.
Python 3.5.0 alpha 3: Python 3 5 0 alpha 3.
Python 3.5.0 alpha 2: Python 3 5 0 alpha 2.
Python 3.5.0 alpha 1: Python 3 5 0 alpha 1.

Python 3.10.12 final

Security
Library
Documentation: Documentation<2>.
Build

Python 3.10.11 final

Security: Security<2>.
Core and Builtins
Library: Library<2>.
Documentation: Documentation<3>.
Tests
Build: Build<2>.
Windows
macOS

Python 3.10.10 final

Core and Builtins: Core and Builtins<2>.
Library: Library<3>.
Documentation: Documentation<4>.
Tests: Tests<2>.
Build: Build<3>.
Windows: Windows<2>.
macOS: macOS<2>.
C API

Python 3.10.9 final

Security: Security<3>.
Core and Builtins: Core and Builtins<3>.
Library: Library<4>.
Documentation: Documentation<5>.
Tests: Tests<3>.
Build: Build<4>.
Windows: Windows<3>.
macOS: macOS<3>.
IDLE: IDLE<3>.
Tools/Demos

Python 3.10.8 final

Security: Security<4>.
Core and Builtins: Core and Builtins<4>.
Library: Library<5>.
Documentation: Documentation<6>.
Build: Build<5>.
Windows: Windows<4>.
macOS: macOS<4>.

Python 3.10.7 final

Security: Security<5>.
Core and Builtins: Core and Builtins<5>.
Library: Library<6>.
Documentation: Documentation<7>.
Tests: Tests<4>.
Build: Build<6>.
IDLE: IDLE<4>.

Python 3.10.6 final

Security: Security<6>.
Core and Builtins: Core and Builtins<6>.
Library: Library<7>.
Documentation: Documentation<8>.
Tests: Tests<5>.
Build: Build<7>.
Windows: Windows<5>.
IDLE: IDLE<5>.
Tools/Demos: Tools/Demos<2>.
C API: C API<2>.

Python 3.10.5 final

Core and Builtins: Core and Builtins<7>.
Library: Library<8>.
Documentation: Documentation<9>.
Tests: Tests<6>.
Build: Build<8>.
Windows: Windows<6>.
Tools/Demos: Tools/Demos<3>.

Python 3.10.4 final

Core and Builtins: Core and Builtins<8>.
Library: Library<9>.

Python 3.10.3 final

Core and Builtins: Core and Builtins<9>.
Library: Library<10>.
Documentation: Documentation<10>.
Tests: Tests<7>.
Build: Build<9>.
Windows: Windows<7>.
macOS: macOS<5>.
IDLE: IDLE<6>.
C API: C API<3>.

Python 3.10.2 final

Core and Builtins: Core and Builtins<10>.
Library: Library<11>.
Documentation: Documentation<11>.
Tests: Tests<8>.
Build: Build<10>.
macOS: macOS<6>.
C API: C API<4>.

Python 3.10.1 final

Core and Builtins: Core and Builtins<11>.
Library: Library<12>.
Documentation: Documentation<12>.
Tests: Tests<9>.
Build: Build<11>.
Windows: Windows<8>.
macOS: macOS<7>.
IDLE: IDLE<7>.
Tools/Demos: Tools/Demos<4>.
C API: C API<5>.

Python 3.10.0 final

Core and Builtins: Core and Builtins<12>.
Library: Library<13>.
Documentation: Documentation<13>.
Tests: Tests<10>.
Build: Build<12>.
IDLE: IDLE<8>.
C API: C API<6>.

Python 3.10.0 release candidate 2

Security: Security<7>.
Core and Builtins: Core and Builtins<13>.
Library: Library<14>.
Documentation: Documentation<14>.
Tests: Tests<11>.
Windows: Windows<9>.
macOS: macOS<8>.

Python 3.10.0 release candidate 1

Security: Security<8>.
Core and Builtins: Core and Builtins<14>.
Library: Library<15>.
Documentation: Documentation<15>.
Tests: Tests<12>.
Windows: Windows<10>.
macOS: macOS<9>.
Tools/Demos: Tools/Demos<5>.
C API: C API<7>.

Python 3.10.0 beta 4

Security: Security<9>.
Core and Builtins: Core and Builtins<15>.
Library: Library<16>.
Documentation: Documentation<16>.
Tests: Tests<13>.
Build: Build<13>.
Windows: Windows<11>.
C API: C API<8>.

Python 3.10.0 beta 3

Core and Builtins: Core and Builtins<16>.
Library: Library<17>.
Documentation: Documentation<17>.
Tests: Tests<14>.
Build: Build<14>.
IDLE: IDLE<9>.
C API: C API<9>.

Python 3.10.0 beta 2

Security: Security<10>.
Core and Builtins: Core and Builtins<17>.
Library: Library<18>.
Documentation: Documentation<18>.
Tests: Tests<15>.
Build: Build<15>.
Windows: Windows<12>.
macOS: macOS<10>.
IDLE: IDLE<10>.
Tools/Demos: Tools/Demos<6>.
C API: C API<10>.

Python 3.10.0 beta 1

Security: Security<11>.
Core and Builtins: Core and Builtins<18>.
Library: Library<19>.
Documentation: Documentation<19>.
Tests: Tests<16>.
Build: Build<16>.
Windows: Windows<13>.
macOS: macOS<11>.
IDLE: IDLE<11>.
C API: C API<11>.

Python 3.10.0 alpha 7

Security: Security<12>.
Core and Builtins: Core and Builtins<19>.
Library: Library<20>.
Documentation: Documentation<20>.
Tests: Tests<17>.
Build: Build<17>.
Windows: Windows<14>.
IDLE: IDLE<12>.
C API: C API<12>.

Python 3.10.0 alpha 6

Security: Security<13>.
Core and Builtins: Core and Builtins<20>.
Library: Library<21>.
Documentation: Documentation<21>.
Tests: Tests<18>.
Build: Build<18>.
Windows: Windows<15>.
macOS: macOS<12>.
IDLE: IDLE<13>.
C API: C API<13>.

Python 3.10.0 alpha 5

Security: Security<14>.
Core and Builtins: Core and Builtins<21>.
Library: Library<22>.
Documentation: Documentation<22>.
Tests: Tests<19>.
Build: Build<19>.
Windows: Windows<16>.
macOS: macOS<13>.
IDLE: IDLE<14>.
C API: C API<14>.

Python 3.10.0 alpha 4

Core and Builtins: Core and Builtins<22>.
Library: Library<23>.
Documentation: Documentation<23>.
Tests: Tests<20>.
Build: Build<20>.
macOS: macOS<14>.
Tools/Demos: Tools/Demos<7>.
C API: C API<15>.

Python 3.10.0 alpha 3

Security: Security<15>.
Core and Builtins: Core and Builtins<23>.
Library: Library<24>.
Documentation: Documentation<24>.
Tests: Tests<21>.
Build: Build<21>.
Windows: Windows<17>.
macOS: macOS<15>.
IDLE: IDLE<15>.
Tools/Demos: Tools/Demos<8>.
C API: C API<16>.

Python 3.10.0 alpha 2

Security: Security<16>.
Core and Builtins: Core and Builtins<24>.
Library: Library<25>.
Documentation: Documentation<25>.
Tests: Tests<22>.
Build: Build<22>.
Windows: Windows<18>.
macOS: macOS<16>.
IDLE: IDLE<16>.
C API: C API<17>.

Python 3.10.0 alpha 1

Security: Security<17>.
Core and Builtins: Core and Builtins<25>.
Library: Library<26>.
Documentation: Documentation<26>.
Tests: Tests<23>.
Build: Build<23>.
Windows: Windows<19>.
macOS: macOS<17>.
IDLE: IDLE<17>.
C API: C API<18>.

Python 3.9.0 beta 1

Security: Security<18>.
Core and Builtins: Core and Builtins<26>.
Library: Library<27>.
Documentation: Documentation<27>.
Tests: Tests<24>.
Build: Build<24>.
Windows: Windows<20>.
macOS: macOS<18>.
Tools/Demos: Tools/Demos<9>.
C API: C API<19>.

Python 3.9.0 alpha 6

Security: Security<19>.
Core and Builtins: Core and Builtins<27>.
Library: Library<28>.
Documentation: Documentation<28>.
Tests: Tests<25>.
Build: Build<25>.
Windows: Windows<21>.
macOS: macOS<19>.
IDLE: IDLE<18>.
Tools/Demos: Tools/Demos<10>.
C API: C API<20>.

Python 3.9.0 alpha 5

Security: Security<20>.
Core and Builtins: Core and Builtins<28>.
Library: Library<29>.
Documentation: Documentation<29>.
Tests: Tests<26>.
Build: Build<26>.
Windows: Windows<22>.
macOS: macOS<20>.
IDLE: IDLE<19>.
Tools/Demos: Tools/Demos<11>.
C API: C API<21>.

Python 3.9.0 alpha 4

Security: Security<21>.
Core and Builtins: Core and Builtins<29>.
Library: Library<30>.
Documentation: Documentation<30>.
Tests: Tests<27>.
Build: Build<27>.
Windows: Windows<23>.
IDLE: IDLE<20>.
C API: C API<22>.

Python 3.9.0 alpha 3

Core and Builtins: Core and Builtins<30>.
Library: Library<31>.
Documentation: Documentation<31>.
Build: Build<28>.
IDLE: IDLE<21>.
C API: C API<23>.

Python 3.9.0 alpha 2

Security: Security<22>.
Core and Builtins: Core and Builtins<31>.
Library: Library<32>.
Documentation: Documentation<32>.
Tests: Tests<28>.
Build: Build<29>.
Windows: Windows<24>.
macOS: macOS<21>.
IDLE: IDLE<22>.
C API: C API<24>.

Python 3.9.0 alpha 1

Security: Security<23>.
Core and Builtins: Core and Builtins<32>.
Library: Library<33>.
Documentation: Documentation<33>.
Tests: Tests<29>.
Build: Build<30>.
Windows: Windows<25>.
macOS: macOS<22>.
IDLE: IDLE<23>.
Tools/Demos: Tools/Demos<12>.
C API: C API<25>.

Python 3.8.0 beta 1

Security: Security<24>.
Core and Builtins: Core and Builtins<33>.
Library: Library<34>.
Documentation: Documentation<34>.
Tests: Tests<30>.
Build: Build<31>.
Windows: Windows<26>.
macOS: macOS<23>.
IDLE: IDLE<24>.
Tools/Demos: Tools/Demos<13>.
C API: C API<26>.

Python 3.8.0 alpha 4

Security: Security<25>.
Core and Builtins: Core and Builtins<34>.
Library: Library<35>.
Documentation: Documentation<35>.
Tests: Tests<31>.
Build: Build<32>.
Windows: Windows<27>.
macOS: macOS<24>.
IDLE: IDLE<25>.
Tools/Demos: Tools/Demos<14>.
C API: C API<27>.

Python 3.8.0 alpha 3

Security: Security<26>.
Core and Builtins: Core and Builtins<35>.
Library: Library<36>.
Documentation: Documentation<36>.
Tests: Tests<32>.
Build: Build<33>.
Windows: Windows<28>.
IDLE: IDLE<26>.
Tools/Demos: Tools/Demos<15>.
C API: C API<28>.

Python 3.8.0 alpha 2

Core and Builtins: Core and Builtins<36>.
Library: Library<37>.
Documentation: Documentation<37>.
Tests: Tests<33>.
Windows: Windows<29>.
IDLE: IDLE<27>.

Python 3.8.0 alpha 1

Security: Security<27>.
Core and Builtins: Core and Builtins<37>.
Library: Library<38>.
Documentation: Documentation<38>.
Tests: Tests<34>.
Build: Build<34>.
Windows: Windows<30>.
macOS: macOS<25>.
IDLE: IDLE<28>.
Tools/Demos: Tools/Demos<16>.
C API: C API<29>.

Python 3.7.0 final

Library: Library<39>.
C API: C API<30>.

Python 3.7.0 release candidate 1

Core and Builtins: Core and Builtins<38>.
Library: Library<40>.
Documentation: Documentation<39>.
Build: Build<35>.
Windows: Windows<31>.
IDLE: IDLE<29>.

Python 3.7.0 beta 5

Core and Builtins: Core and Builtins<39>.
Library: Library<41>.
Documentation: Documentation<40>.
Tests: Tests<35>.
Build: Build<36>.
macOS: macOS<26>.
IDLE: IDLE<30>.

Python 3.7.0 beta 4

Core and Builtins: Core and Builtins<40>.
Library: Library<42>.
Documentation: Documentation<41>.
Tests: Tests<36>.
Build: Build<37>.
Windows: Windows<32>.
macOS: macOS<27>.
IDLE: IDLE<31>.
Tools/Demos: Tools/Demos<17>.

Python 3.7.0 beta 3

Security: Security<28>.
Core and Builtins: Core and Builtins<41>.
Library: Library<43>.
Documentation: Documentation<42>.
Tests: Tests<37>.
Build: Build<38>.
Windows: Windows<33>.
macOS: macOS<28>.
IDLE: IDLE<32>.
Tools/Demos: Tools/Demos<18>.
C API: C API<31>.

Python 3.7.0 beta 2

Security: Security<29>.
Core and Builtins: Core and Builtins<42>.
Library: Library<44>.
Documentation: Documentation<43>.
Tests: Tests<38>.
Build: Build<39>.
Windows: Windows<34>.
macOS: macOS<29>.
IDLE: IDLE<33>.
Tools/Demos: Tools/Demos<19>.

Python 3.7.0 beta 1

Core and Builtins: Core and Builtins<43>.
Library: Library<45>.
Documentation: Documentation<44>.
Tests: Tests<39>.
Build: Build<40>.
Windows: Windows<35>.
macOS: macOS<30>.
C API: C API<32>.

Python 3.7.0 alpha 4

Core and Builtins: Core and Builtins<44>.
Library: Library<46>.
Documentation: Documentation<45>.
Tests: Tests<40>.
Windows: Windows<36>.
Tools/Demos: Tools/Demos<20>.
C API: C API<33>.

Python 3.7.0 alpha 3

Core and Builtins: Core and Builtins<45>.
Library: Library<47>.
Documentation: Documentation<46>.
Tests: Tests<41>.
Build: Build<41>.
Windows: Windows<37>.
macOS: macOS<31>.
IDLE: IDLE<34>.
Tools/Demos: Tools/Demos<21>.
C API: C API<34>.

Python 3.7.0 alpha 2

Core and Builtins: Core and Builtins<46>.
Library: Library<48>.
Documentation: Documentation<47>.
Build: Build<42>.
IDLE: IDLE<35>.
C API: C API<35>.

Python 3.7.0 alpha 1

Security: Security<30>.
Core and Builtins: Core and Builtins<47>.
Library: Library<49>.
Documentation: Documentation<48>.
Tests: Tests<42>.
Build: Build<43>.
Windows: Windows<38>.
IDLE: IDLE<36>.
Tools/Demos: Tools/Demos<22>.
C API: C API<36>.

Python 3.6.6 release candidate 1

Core and Builtins: Core and Builtins<48>.
Library: Library<50>.
Documentation: Documentation<49>.
Tests: Tests<43>.
Build: Build<44>.
Windows: Windows<39>.
macOS: macOS<32>.
IDLE: IDLE<37>.
Tools/Demos: Tools/Demos<23>.
C API: C API<37>.

Python 3.6.5 final

Tests: Tests<44>.
Build: Build<45>.

Python 3.6.5 release candidate 1

Security: Security<31>.
Core and Builtins: Core and Builtins<49>.
Library: Library<51>.
Documentation: Documentation<50>.
Tests: Tests<45>.
Build: Build<46>.
Windows: Windows<40>.
macOS: macOS<33>.
IDLE: IDLE<38>.
Tools/Demos: Tools/Demos<24>.
C API: C API<38>.

Python 3.6.4 release candidate 1

Core and Builtins: Core and Builtins<50>.
Library: Library<52>.
Documentation: Documentation<51>.
Tests: Tests<46>.
Build: Build<47>.
Windows: Windows<41>.
macOS: macOS<34>.
IDLE: IDLE<39>.
Tools/Demos: Tools/Demos<25>.
C API: C API<39>.

Python 3.6.3 final

Library: Library<53>.
Build: Build<48>.

Python 3.6.3 release candidate 1

Security: Security<32>.
Core and Builtins: Core and Builtins<51>.
Library: Library<54>.
Documentation: Documentation<52>.
Tests: Tests<47>.
Build: Build<49>.
Windows: Windows<42>.
IDLE: IDLE<40>.
Tools/Demos: Tools/Demos<26>.

Python 3.6.2 release candidate 2

Security: Security<33>.

Python 3.6.2 release candidate 1

Security: Security<34>.
Core and Builtins: Core and Builtins<52>.
Library: Library<55>.
IDLE: IDLE<41>.
C API: C API<40>.
Build: Build<50>.
Documentation: Documentation<53>.
Tools/Demos: Tools/Demos<27>.
Tests: Tests<48>.
Windows: Windows<43>.

Python 3.6.1 final

Core and Builtins: Core and Builtins<53>.
Build: Build<51>.

Python 3.6.1 release candidate 1

Core and Builtins: Core and Builtins<54>.
Library: Library<56>.
IDLE: IDLE<42>.
Windows: Windows<44>.
C API: C API<41>.
Documentation: Documentation<54>.
Tests: Tests<49>.
Build: Build<52>.

Python 3.6.0 release candidate 2

Core and Builtins: Core and Builtins<55>.
Tools/Demos: Tools/Demos<28>.
Windows: Windows<45>.
Build: Build<53>.

Python 3.6.0 release candidate 1

Core and Builtins: Core and Builtins<56>.
Library: Library<57>.
C API: C API<42>.
Documentation: Documentation<55>.
Tools/Demos: Tools/Demos<29>.

Python 3.6.0 beta 4

Core and Builtins: Core and Builtins<57>.
Library: Library<58>.
Documentation: Documentation<56>.
Tests: Tests<50>.
Build: Build<54>.

Python 3.6.0 beta 3

Core and Builtins: Core and Builtins<58>.
Library: Library<59>.
Windows: Windows<46>.
Build: Build<55>.
Tests: Tests<51>.

Python 3.6.0 beta 2

Core and Builtins: Core and Builtins<59>.
Library: Library<60>.
Windows: Windows<47>.
C API: C API<43>.
Build: Build<56>.
Tests: Tests<52>.

Python 3.6.0 beta 1

Core and Builtins: Core and Builtins<60>.
Library: Library<61>.
IDLE: IDLE<43>.
C API: C API<44>.
Tests: Tests<53>.
Build: Build<57>.
Tools/Demos: Tools/Demos<30>.
Windows: Windows<48>.

Python 3.6.0 alpha 4

Core and Builtins: Core and Builtins<61>.
Library: Library<62>.
IDLE: IDLE<44>.
Tests: Tests<54>.
Windows: Windows<49>.
Build: Build<58>.

Python 3.6.0 alpha 3

Security: Security<35>.
Core and Builtins: Core and Builtins<62>.
Library: Library<63>.
IDLE: IDLE<45>.
C API: C API<45>.
Build: Build<59>.
Tools/Demos: Tools/Demos<31>.
Documentation: Documentation<57>.
Tests: Tests<55>.

Python 3.6.0 alpha 2

Security: Security<36>.
Core and Builtins: Core and Builtins<63>.
Library: Library<64>.
IDLE: IDLE<46>.
Documentation: Documentation<58>.
Tests: Tests<56>.
Windows: Windows<50>.
Build: Build<60>.
C API: C API<46>.
Tools/Demos: Tools/Demos<32>.

Python 3.6.0 alpha 1

Security: Security<37>.
Core and Builtins: Core and Builtins<64>.
Library: Library<65>.
IDLE: IDLE<47>.
Documentation: Documentation<59>.
Tests: Tests<57>.
Build: Build<61>.
Windows: Windows<51>.
Tools/Demos: Tools/Demos<33>.
C API: C API<47>.

Python 3.5.5 release candidate 1

Security: Security<38>.
Core and Builtins: Core and Builtins<65>.
Library: Library<66>.

Python 3.5.4 final

Library: Library<67>.

Python 3.5.4 release candidate 1

Security: Security<39>.
Core and Builtins: Core and Builtins<66>.
Library: Library<68>.
Documentation: Documentation<60>.
Tests: Tests<58>.
Build: Build<62>.
Windows: Windows<52>.
C API: C API<48>.

Python 3.5.3 release candidate 1

Security: Security<40>.
Core and Builtins: Core and Builtins<67>.
Library: Library<69>.
IDLE: IDLE<48>.
C API: C API<49>.
Documentation: Documentation<61>.
Tests: Tests<59>.
Tools/Demos: Tools/Demos<34>.
Windows: Windows<53>.
Build: Build<63>.

Python 3.5.2 final

Core and Builtins: Core and Builtins<68>.
Tests: Tests<60>.
IDLE: IDLE<49>.

Python 3.5.2 release candidate 1

Security: Security<41>.
Core and Builtins: Core and Builtins<69>.
Library: Library<70>.
IDLE: IDLE<50>.
Documentation: Documentation<62>.
Tests: Tests<61>.
Build: Build<64>.
Windows: Windows<54>.
Tools/Demos: Tools/Demos<35>.

Python 3.5.1 final

Core and Builtins: Core and Builtins<70>.
Windows: Windows<55>.

Python 3.5.1 release candidate 1

Core and Builtins: Core and Builtins<71>.
Library: Library<71>.
IDLE: IDLE<51>.
Documentation: Documentation<63>.
Tests: Tests<62>.
Build: Build<65>.
Windows: Windows<56>.
Tools/Demos: Tools/Demos<36>.

Python 3.5.0 final

Build: Build<66>.

Python 3.5.0 release candidate 4

Library: Library<72>.
Build: Build<67>.

Python 3.5.0 release candidate 3

Core and Builtins: Core and Builtins<72>.
Library: Library<73>.

Python 3.5.0 release candidate 2

Core and Builtins: Core and Builtins<73>.
Library: Library<74>.

Python 3.5.0 release candidate 1

Core and Builtins: Core and Builtins<74>.
Library: Library<75>.
IDLE: IDLE<52>.
Documentation: Documentation<64>.
Tests: Tests<63>.

Python 3.5.0 beta 4

Core and Builtins: Core and Builtins<75>.
Library: Library<76>.
Build: Build<68>.

Python 3.5.0 beta 3

Core and Builtins: Core and Builtins<76>.
Library: Library<77>.
Tests: Tests<64>.
Documentation: Documentation<65>.
Build: Build<69>.

Python 3.5.0 beta 2

Core and Builtins: Core and Builtins<77>.
Library: Library<78>.

Python 3.5.0 beta 1

Core and Builtins: Core and Builtins<78>.
Library: Library<79>.
IDLE: IDLE<53>.
Tests: Tests<65>.
Documentation: Documentation<66>.
Tools/Demos: Tools/Demos<37>.

Python 3.5.0 alpha 4

Core and Builtins: Core and Builtins<79>.
Library: Library<80>.
Build: Build<70>.
Tests: Tests<66>.
Tools/Demos: Tools/Demos<38>.
C API: C API<50>.

Python 3.5.0 alpha 3

Core and Builtins: Core and Builtins<80>.
Library: Library<81>.
Build: Build<71>.
Tests: Tests<67>.
Tools/Demos: Tools/Demos<39>.

Python 3.5.0 alpha 2

Core and Builtins: Core and Builtins<81>.
Library: Library<82>.
Build: Build<72>.
C API: C API<51>.
Windows: Windows<57>.

Python 3.5.0 alpha 1

Core and Builtins: Core and Builtins<82>.
Library: Library<83>.
IDLE: IDLE<54>.
Build: Build<73>.
C API: C API<52>.
Documentation: Documentation<67>.
Tests: Tests<68>.
Tools/Demos: Tools/Demos<40>.
Windows: Windows<58>.

The Python Tutorial

Whetting Your Appetite
Using the Python Interpreter
An Informal Introduction to Python
More Control Flow Tools
Data Structures
Modules
Input and Output
Errors and Exceptions
Classes
Brief Tour of the Standard Library
Brief Tour of the Standard Library — Part II
Virtual Environments and Packages
What Now?
Interactive Input Editing and History Substitution
Floating Point Arithmetic; Issues and Limitations: Floating Point Arithmetic Issues and Limitations.
Appendix

Using the Python Interpreter

Invoking the Interpreter
The Interpreter and Its Environment

Invoking the Interpreter

Argument Passing
Interactive Mode

The Interpreter and Its Environment

Source Code Encoding

An Informal Introduction to Python

Using Python as a Calculator
First Steps Towards Programming

Using Python as a Calculator

Numbers
Strings
Lists

More Control Flow Tools

if Statements
for Statements
The range() Function: The range Function.
break and continue Statements, and else Clauses on Loops: break and continue Statements and else Clauses on Loops.
pass Statements
match Statements
Defining Functions
More on Defining Functions
Intermezzo; Coding Style: Intermezzo Coding Style.

More on Defining Functions

Default Argument Values
Keyword Arguments
Special parameters
Arbitrary Argument Lists
Unpacking Argument Lists
Lambda Expressions
Documentation Strings
Function Annotations

Special parameters

Positional-or-Keyword Arguments
Positional-Only Parameters
Keyword-Only Arguments
Function Examples
Recap

Data Structures

More on Lists
The del statement
Tuples and Sequences
Sets
Dictionaries
Looping Techniques
More on Conditions
Comparing Sequences and Other Types

More on Lists

Using Lists as Stacks
Using Lists as Queues
List Comprehensions: List Comprehensions<2>.
Nested List Comprehensions

Modules

More on Modules
Standard Modules
The dir() Function: The dir Function.
Packages

More on Modules

Executing modules as scripts
The Module Search Path
“Compiled” Python files

Packages

Importing * From a Package
Intra-package References
Packages in Multiple Directories

Input and Output

Fancier Output Formatting
Reading and Writing Files

Fancier Output Formatting

Formatted String Literals
The String format() Method: The String format Method.
Manual String Formatting
Old string formatting

Reading and Writing Files

Methods of File Objects
Saving structured data with json

Errors and Exceptions

Syntax Errors
Exceptions
Handling Exceptions
Raising Exceptions
Exception Chaining
User-defined Exceptions
Defining Clean-up Actions
Predefined Clean-up Actions

Classes

A Word About Names and Objects
Python Scopes and Namespaces
A First Look at Classes
Random Remarks
Inheritance
Private Variables
Odds and Ends
Iterators
Generators
Generator Expressions

Python Scopes and Namespaces

Scopes and Namespaces Example

A First Look at Classes

Class Definition Syntax
Class Objects
Instance Objects
Method Objects
Class and Instance Variables

Inheritance

Multiple Inheritance

Brief Tour of the Standard Library

Operating System Interface
File Wildcards
Command Line Arguments
Error Output Redirection and Program Termination
String Pattern Matching
Mathematics
Internet Access
Dates and Times
Data Compression
Performance Measurement
Quality Control
Batteries Included

Brief Tour of the Standard Library — Part II

Output Formatting
Templating
Working with Binary Data Record Layouts
Multi-threading: Multi-threading<2>.
Logging
Weak References
Tools for Working with Lists
Decimal Floating Point Arithmetic

Virtual Environments and Packages

Introduction: Introduction<4>.
Creating Virtual Environments
Managing Packages with pip

Interactive Input Editing and History Substitution

Tab Completion and History Editing
Alternatives to the Interactive Interpreter

Floating Point Arithmetic: Issues and Limitations

Representation Error

Appendix

Interactive Mode: Interactive Mode<2>.

Interactive Mode

Error Handling
Executable Python Scripts
The Interactive Startup File
The Customization Modules

Python Setup and Usage

Command line and environment
Using Python on Unix platforms
Configure Python
Using Python on Windows
Using Python on a Mac
Editors and IDEs

Command line and environment

Command line
Environment variables

Command line

Interface options
Generic options
Miscellaneous options
Options you shouldn’t use

Environment variables

Debug-mode variables

Using Python on Unix platforms

Getting and installing the latest version of Python
Building Python
Python-related paths and files
Miscellaneous
Custom OpenSSL

Getting and installing the latest version of Python

On Linux
On FreeBSD and OpenBSD
On OpenSolaris

Configure Python

Configure Options
Python Build System
Compiler and linker flags

Configure Options

General Options
Install Options
Performance options
Python Debug Build
Debug options
Linker options
Libraries options
Security Options
macOS Options

Python Build System

Main files of the build system
Main build steps
Main Makefile targets
C extensions

Compiler and linker flags

Preprocessor flags
Compiler flags
Linker flags

Using Python on Windows

The full installer
The Microsoft Store package
The nuget.org packages: The nuget org packages.
The embeddable package
Alternative bundles
Configuring Python
UTF-8 mode
Python Launcher for Windows
Finding modules
Additional modules
Compiling Python on Windows
Other Platforms

The full installer

Installation steps
Removing the MAX_PATH Limitation
Installing Without UI
Installing Without Downloading
Modifying an install

The Microsoft Store package

Known issues

Known issues

Redirection of local data, registry, and temporary paths: Redirection of local data registry and temporary paths.

The embeddable package

Python Application
Embedding Python

Configuring Python

Excursus; Setting environment variables: Excursus Setting environment variables.
Finding the Python executable

Python Launcher for Windows

Getting started
Shebang Lines
Arguments in shebang lines
Customization
Diagnostics

Getting started

From the command-line
Virtual environments
From a script
From file associations

Customization

Customization via INI files
Customizing default Python versions

Additional modules

PyWin32
cx_Freeze

Using Python on a Mac

Getting and Installing MacPython
The IDE
Installing Additional Python Packages
GUI Programming on the Mac
Distributing Python Applications on the Mac
Other Resources

Getting and Installing MacPython

How to run a Python script
Running scripts with a GUI
Configuration

The Python Language Reference

Introduction: Introduction<5>.
Lexical analysis
Data model
Execution model
The import system
Expressions
Simple statements
Compound statements
Top-level components
Full Grammar specification

Introduction

Alternate Implementations
Notation

Lexical analysis

Line structure
Other tokens
Identifiers and keywords
Literals
Operators
Delimiters

Line structure

Logical lines
Physical lines
Comments
Encoding declarations
Explicit line joining
Implicit line joining
Blank lines
Indentation
Whitespace between tokens

Identifiers and keywords

Keywords
Soft Keywords
Reserved classes of identifiers

Literals

String and Bytes literals
String literal concatenation
Formatted string literals
Numeric literals
Integer literals
Floating point literals
Imaginary literals

Data model

Objects, values and types: Objects values and types.
The standard type hierarchy
Special method names
Coroutines

Special method names

Basic customization
Customizing attribute access
Customizing class creation
Customizing instance and subclass checks
Emulating generic types
Emulating callable objects
Emulating container types
Emulating numeric types
With Statement Context Managers
Customizing positional arguments in class pattern matching
Special method lookup

Customizing attribute access

Customizing module attribute access
Implementing Descriptors
Invoking Descriptors
__slots__: __slots__<2>.

__slots__

Notes on using __slots__

Customizing class creation

Metaclasses
Resolving MRO entries
Determining the appropriate metaclass
Preparing the class namespace
Executing the class body
Creating the class object
Uses for metaclasses

Emulating generic types

The purpose of __class_getitem__
__class_getitem__ versus __getitem__

Coroutines

Awaitable Objects
Coroutine Objects
Asynchronous Iterators
Asynchronous Context Managers

Execution model

Structure of a program
Naming and binding
Exceptions: Exceptions<2>.

Naming and binding

Binding of names
Resolution of names
Builtins and restricted execution
Interaction with dynamic features

The import system

importlib: importlib<8>.
Packages: Packages<2>.
Searching
Loading
The Path Based Finder
Replacing the standard import system
Package Relative Imports
Special considerations for __main__
References

Packages

Regular packages
Namespace packages

Searching

The module cache
Finders and loaders
Import hooks
The meta path

Loading

Loaders
Submodules
Module spec
Import-related module attributes
module.__path__: module __path__.
Module reprs
Cached bytecode invalidation

The Path Based Finder

Path entry finders
Path entry finder protocol

Special considerations for __main__

__main__.__spec__: __main__ __spec__.

Expressions

Arithmetic conversions
Atoms
Primaries
Await expression
The power operator
Unary arithmetic and bitwise operations
Binary arithmetic operations
Shifting operations
Binary bitwise operations
Comparisons
Boolean operations
Assignment expressions: Assignment expressions<2>.
Conditional expressions
Lambdas
Expression lists
Evaluation order
Operator precedence

Atoms

Identifiers (Names): Identifiers Names.
Literals: Literals<2>.
Parenthesized forms
Displays for lists, sets and dictionaries: Displays for lists sets and dictionaries.
List displays
Set displays
Dictionary displays
Generator expressions
Yield expressions

Yield expressions

Generator-iterator methods
Examples
Asynchronous generator functions
Asynchronous generator-iterator methods

Primaries

Attribute references
Subscriptions
Slicings
Calls

Comparisons

Value comparisons
Membership test operations
Identity comparisons

Simple statements

Expression statements
Assignment statements
The assert statement
The pass statement
The del statement: The del statement<2>.
The return statement
The yield statement
The raise statement
The break statement
The continue statement
The import statement
The global statement
The nonlocal statement

Assignment statements

Augmented assignment statements
Annotated assignment statements

The import statement

Future statements

Compound statements

The if statement
The while statement
The for statement
The try statement
The with statement
The match statement
Function definitions
Class definitions
Coroutines: Coroutines<2>.

The match statement

Overview
Guards
Irrefutable Case Blocks
Patterns

Patterns

OR Patterns
AS Patterns
Literal Patterns
Capture Patterns
Wildcard Patterns
Value Patterns
Group Patterns
Sequence Patterns
Mapping Patterns
Class Patterns

Coroutines

Coroutine function definition
The async for statement
The async with statement

Top-level components

Complete Python programs
File input
Interactive input
Expression input

The Python Standard Library

Introduction: Introduction<6>.
Built-in Functions
Built-in Constants
Built-in Types
Built-in Exceptions
Text Processing Services
Binary Data Services
Data Types
Numeric and Mathematical Modules
Functional Programming Modules
File and Directory Access
Data Persistence
Data Compression and Archiving
File Formats
Cryptographic Services
Generic Operating System Services
Concurrent Execution
Networking and Interprocess Communication
Internet Data Handling
Structured Markup Processing Tools
Internet Protocols and Support
Multimedia Services
Internationalization
Program Frameworks
Graphical User Interfaces with Tk
Development Tools
Debugging and Profiling
Software Packaging and Distribution
Python Runtime Services
Custom Python Interpreters
Importing Modules
Python Language Services
MS Windows Specific Services
Unix Specific Services
Superseded Modules
Security Considerations: Security Considerations<4>.

Introduction

Notes on availability

Built-in Constants

Constants added by the site module

Built-in Types

Truth Value Testing
Boolean Operations — and, or, not: Boolean Operations — and or not.
Comparisons: Comparisons<2>.
Numeric Types — int, float, complex: Numeric Types — int float complex.
Iterator Types
Sequence Types — list, tuple, range: Sequence Types — list tuple range.
Text Sequence Type — str
Binary Sequence Types — bytes, bytearray, memoryview: Binary Sequence Types — bytes bytearray memoryview.
Set Types — set, frozenset: Set Types — set frozenset.
Mapping Types — dict
Context Manager Types
Type Annotation Types — Generic Alias, Union: Type Annotation Types — Generic Alias Union.
Other Built-in Types
Special Attributes
Integer string conversion length limitation

Numeric Types — int, float, complex

Bitwise Operations on Integer Types
Additional Methods on Integer Types
Additional Methods on Float
Hashing of numeric types

Iterator Types

Generator Types

Sequence Types — list, tuple, range

Common Sequence Operations
Immutable Sequence Types
Mutable Sequence Types
Lists: Lists<2>.
Tuples
Ranges

Text Sequence Type — str

String Methods: String Methods<2>.
printf-style String Formatting

Binary Sequence Types — bytes, bytearray, memoryview

Bytes Objects
Bytearray Objects
Bytes and Bytearray Operations
printf-style Bytes Formatting
Memory Views

Mapping Types — dict

Dictionary view objects

Type Annotation Types — Generic Alias, Union

Generic Alias Type
Union Type

Generic Alias Type

Standard Generic Classes
Special Attributes of GenericAlias objects

Other Built-in Types

Modules: Modules<2>.
Classes and Class Instances
Functions
Methods
Code Objects
Type Objects
The Null Object
The Ellipsis Object
The NotImplemented Object
Boolean Values
Internal Objects

Integer string conversion length limitation

Affected APIs
Configuring the limit
Recommended configuration

Built-in Exceptions

Exception context
Inheriting from built-in exceptions
Base classes
Concrete exceptions
Warnings
Exception hierarchy

Concrete exceptions

OS exceptions

Text Processing Services

string — Common string operations
re — Regular expression operations
difflib — Helpers for computing deltas
textwrap — Text wrapping and filling
unicodedata — Unicode Database
stringprep — Internet String Preparation
readline — GNU readline interface
rlcompleter — Completion function for GNU readline

string — Common string operations

String constants
Custom String Formatting
Format String Syntax
Template strings
Helper functions

Format String Syntax

Format Specification Mini-Language
Format examples

re — Regular expression operations

Regular Expression Syntax
Module Contents
Regular Expression Objects
Match Objects
Regular Expression Examples

Module Contents

Flags
Functions: Functions<2>.
Exceptions: Exceptions<3>.

Regular Expression Examples

Checking for a Pair
Simulating scanf(): Simulating scanf.
search() vs. match(): search vs match.
Making a Phonebook
Text Munging
Finding all Adverbs
Finding all Adverbs and their Positions
Raw String Notation
Writing a Tokenizer

difflib — Helpers for computing deltas

SequenceMatcher Objects
SequenceMatcher Examples
Differ Objects
Differ Example
A command-line interface to difflib

readline — GNU readline interface

Init file
Line buffer
History file
History list
Startup hooks
Completion
Example

rlcompleter — Completion function for GNU readline

Completer Objects

Binary Data Services

struct — Interpret bytes as packed binary data
codecs — Codec registry and base classes

struct — Interpret bytes as packed binary data

Functions and Exceptions
Format Strings
Applications
Classes: Classes<2>.

Format Strings

Byte Order, Size, and Alignment: Byte Order Size and Alignment.
Format Characters
Examples: Examples<2>.

Applications

Native Formats
Standard Formats

codecs — Codec registry and base classes

Codec Base Classes
Encodings and Unicode
Standard Encodings
Python Specific Encodings
encodings.idna — Internationalized Domain Names in Applications: encodings idna — Internationalized Domain Names in Applications.
encodings.mbcs — Windows ANSI codepage: encodings mbcs — Windows ANSI codepage.
encodings.utf_8_sig — UTF-8 codec with BOM signature: encodings utf_8_sig — UTF-8 codec with BOM signature.

Codec Base Classes

Error Handlers
Stateless Encoding and Decoding
Incremental Encoding and Decoding
Stream Encoding and Decoding

Incremental Encoding and Decoding

IncrementalEncoder Objects
IncrementalDecoder Objects

Stream Encoding and Decoding

StreamWriter Objects
StreamReader Objects
StreamReaderWriter Objects
StreamRecoder Objects

Python Specific Encodings

Text Encodings
Binary Transforms
Text Transforms

Data Types

datetime — Basic date and time types
zoneinfo — IANA time zone support
calendar — General calendar-related functions
collections — Container datatypes
collections.abc — Abstract Base Classes for Containers: collections abc — Abstract Base Classes for Containers.
heapq — Heap queue algorithm
bisect — Array bisection algorithm
array — Efficient arrays of numeric values
weakref — Weak references
types — Dynamic type creation and names for built-in types
copy — Shallow and deep copy operations
pprint — Data pretty printer
reprlib — Alternate repr() implementation: reprlib — Alternate repr implementation.
enum — Support for enumerations
graphlib — Functionality to operate with graph-like structures

datetime — Basic date and time types

Aware and Naive Objects
Constants
Available Types
timedelta Objects
date Objects
datetime Objects
time Objects
tzinfo Objects
timezone Objects
strftime() and strptime() Behavior: strftime and strptime Behavior.

Available Types

Common Properties
Determining if an Object is Aware or Naive

timedelta Objects

Examples of usage; timedelta: Examples of usage timedelta.

date Objects

Examples of Usage; date: Examples of Usage date.

datetime Objects

Examples of Usage; datetime: Examples of Usage datetime.

time Objects

Examples of Usage; time: Examples of Usage time.

strftime() and strptime() Behavior

strftime() and strptime() Format Codes: strftime and strptime Format Codes.
Technical Detail

zoneinfo — IANA time zone support

Using ZoneInfo
Data sources
The ZoneInfo class
Functions: Functions<3>.
Globals
Exceptions and warnings

Data sources

Configuring the data sources

Configuring the data sources

Compile-time configuration
Environment configuration
Runtime configuration

The ZoneInfo class

String representations
Pickle serialization

collections — Container datatypes

ChainMap objects
Counter objects
deque objects
defaultdict objects
namedtuple() Factory Function for Tuples with Named Fields: namedtuple Factory Function for Tuples with Named Fields.
OrderedDict objects
UserDict objects
UserList objects
UserString objects

ChainMap objects

ChainMap Examples and Recipes

deque objects

deque Recipes

defaultdict objects

defaultdict Examples

OrderedDict objects

OrderedDict Examples and Recipes

collections.abc — Abstract Base Classes for Containers

Collections Abstract Base Classes
Collections Abstract Base Classes – Detailed Descriptions
Examples and Recipes

heapq — Heap queue algorithm

Basic Examples
Priority Queue Implementation Notes
Theory

bisect — Array bisection algorithm

Performance Notes
Searching Sorted Lists
Examples: Examples<3>.

weakref — Weak references

Weak Reference Objects
Example: Example<2>.
Finalizer Objects
Comparing finalizers with __del__() methods: Comparing finalizers with __del__ methods.

types — Dynamic type creation and names for built-in types

Dynamic Type Creation
Standard Interpreter Types
Additional Utility Classes and Functions
Coroutine Utility Functions

pprint — Data pretty printer

PrettyPrinter Objects
Example: Example<3>.

reprlib — Alternate repr() implementation

Repr Objects
Subclassing Repr Objects

enum — Support for enumerations

Module Contents: Module Contents<2>.
Creating an Enum
Programmatic access to enumeration members and their attributes
Duplicating enum members and values
Ensuring unique enumeration values
Using automatic values
Iteration
Comparisons: Comparisons<3>.
Allowed members and attributes of enumerations
Restricted Enum subclassing
Pickling
Functional API
Derived Enumerations
When to use __new__() vs. __init__(): When to use __new__ vs __init__.
Interesting examples
How are Enums different?

Derived Enumerations

IntEnum
IntFlag
Flag
Others

Interesting examples

Omitting values
OrderedEnum
DuplicateFreeEnum
Planet
TimePeriod

Omitting values

Using auto
Using object
Using a descriptive string
Using a custom __new__(): Using a custom __new__.

How are Enums different?

Enum Classes
Enum Members (aka instances): Enum Members aka instances.
Finer Points

Finer Points

Supported __dunder__ names
Supported _sunder_ names
_Private__names
Enum member type
Boolean value of Enum classes and members
Enum classes with methods
Combining members of Flag

graphlib — Functionality to operate with graph-like structures

Exceptions: Exceptions<4>.

Numeric and Mathematical Modules

numbers — Numeric abstract base classes
math — Mathematical functions
cmath — Mathematical functions for complex numbers
decimal — Decimal fixed point and floating point arithmetic
fractions — Rational numbers
random — Generate pseudo-random numbers
statistics — Mathematical statistics functions

numbers — Numeric abstract base classes

The numeric tower
Notes for type implementors

Notes for type implementors

Adding More Numeric ABCs
Implementing the arithmetic operations

math — Mathematical functions

Number-theoretic and representation functions
Power and logarithmic functions
Trigonometric functions
Angular conversion
Hyperbolic functions
Special functions
Constants: Constants<2>.

cmath — Mathematical functions for complex numbers

Conversions to and from polar coordinates
Power and logarithmic functions: Power and logarithmic functions<2>.
Trigonometric functions: Trigonometric functions<2>.
Hyperbolic functions: Hyperbolic functions<2>.
Classification functions
Constants: Constants<3>.

decimal — Decimal fixed point and floating point arithmetic

Quick-start Tutorial
Decimal objects
Context objects
Constants: Constants<4>.
Rounding modes
Signals
Floating Point Notes
Working with threads
Recipes
Decimal FAQ

Decimal objects

Logical operands

Floating Point Notes

Mitigating round-off error with increased precision
Special values

random — Generate pseudo-random numbers

Bookkeeping functions
Functions for bytes
Functions for integers
Functions for sequences
Real-valued distributions
Alternative Generator
Notes on Reproducibility
Examples: Examples<4>.
Recipes: Recipes<2>.

statistics — Mathematical statistics functions

Averages and measures of central location
Measures of spread
Statistics for relations between two inputs
Function details
Exceptions: Exceptions<5>.
NormalDist objects

NormalDist objects

NormalDist Examples and Recipes

Functional Programming Modules

itertools — Functions creating iterators for efficient looping
functools — Higher-order functions and operations on callable objects
operator — Standard operators as functions

itertools — Functions creating iterators for efficient looping

Itertool functions
Itertools Recipes

functools — Higher-order functions and operations on callable objects

partial Objects

operator — Standard operators as functions

Mapping Operators to Functions
In-place Operators

File and Directory Access

pathlib — Object-oriented filesystem paths
os.path — Common pathname manipulations: os path — Common pathname manipulations.
fileinput — Iterate over lines from multiple input streams
stat — Interpreting stat() results: stat — Interpreting stat results.
filecmp — File and Directory Comparisons
tempfile — Generate temporary files and directories
glob — Unix style pathname pattern expansion
fnmatch — Unix filename pattern matching
linecache — Random access to text lines
shutil — High-level file operations

pathlib — Object-oriented filesystem paths

Basic use
Pure paths
Concrete paths
Correspondence to tools in the os module

Pure paths

General properties
Operators: Operators<2>.
Accessing individual parts
Methods and properties

Concrete paths

Methods: Methods<2>.

filecmp — File and Directory Comparisons

The dircmp class

tempfile — Generate temporary files and directories

Examples: Examples<5>.
Deprecated functions and variables

shutil — High-level file operations

Directory and files operations
Archiving operations
Querying the size of the output terminal

Directory and files operations

Platform-dependent efficient copy operations
copytree example
rmtree example

Archiving operations

Archiving example
Archiving example with base_dir

Data Persistence

pickle — Python object serialization
copyreg — Register pickle support functions
shelve — Python object persistence
marshal — Internal Python object serialization
dbm — Interfaces to Unix “databases”
sqlite3 — DB-API 2.0 interface for SQLite databases: sqlite3 — DB-API 2 0 interface for SQLite databases.

pickle — Python object serialization

Relationship to other Python modules
Data stream format
Module Interface
What can be pickled and unpickled?
Pickling Class Instances
Custom Reduction for Types, Functions, and Other Objects: Custom Reduction for Types Functions and Other Objects.
Out-of-band Buffers
Restricting Globals
Performance: Performance<2>.
Examples: Examples<6>.

Relationship to other Python modules

Comparison with marshal
Comparison with json

Pickling Class Instances

Persistence of External Objects
Dispatch Tables
Handling Stateful Objects

Out-of-band Buffers

Provider API
Consumer API
Example: Example<4>.

copyreg — Register pickle support functions

Example: Example<5>.

shelve — Python object persistence

Restrictions
Example: Example<6>.

dbm — Interfaces to Unix “databases”

dbm.gnu — GNU’s reinterpretation of dbm: dbm gnu — GNU’s reinterpretation of dbm.
dbm.ndbm — Interface based on ndbm: dbm ndbm — Interface based on ndbm.
dbm.dumb — Portable DBM implementation: dbm dumb — Portable DBM implementation.

sqlite3 — DB-API 2.0 interface for SQLite databases

Tutorial
Reference
How-to guides
Explanation

Reference

Module functions
Module constants
Connection objects
Cursor objects
Row objects
PrepareProtocol objects
Exceptions: Exceptions<6>.
SQLite and Python types
Default adapters and converters

How-to guides

How to use placeholders to bind values in SQL queries
How to adapt custom Python types to SQLite values
How to convert SQLite values to custom Python types
Adapter and converter recipes
How to use connection shortcut methods
How to use the connection context manager
How to work with SQLite URIs
How to create and use row factories

How to adapt custom Python types to SQLite values

How to write adaptable objects
How to register adapter callables

Explanation

Transaction control

Data Compression and Archiving

zlib — Compression compatible with gzip
gzip — Support for gzip files
bz2 — Support for bzip2 compression
lzma — Compression using the LZMA algorithm
zipfile — Work with ZIP archives
tarfile — Read and write tar archive files

gzip — Support for gzip files

Examples of usage
Command Line Interface

Command Line Interface

Command line options

bz2 — Support for bzip2 compression

(De)compression of files: De compression of files.
Incremental (de)compression: Incremental de compression.
One-shot (de)compression: One-shot de compression.
Examples of usage: Examples of usage<2>.

lzma — Compression using the LZMA algorithm

Reading and writing compressed files
Compressing and decompressing data in memory
Miscellaneous: Miscellaneous<2>.
Specifying custom filter chains
Examples: Examples<7>.

zipfile — Work with ZIP archives

ZipFile Objects
Path Objects
PyZipFile Objects
ZipInfo Objects
Command-Line Interface
Decompression pitfalls

Command-Line Interface

Command-line options

Decompression pitfalls

From file itself
File System limitations
Resources limitations
Interruption
Default behaviors of extraction

tarfile — Read and write tar archive files

TarFile Objects
TarInfo Objects
Extraction filters
Command-Line Interface: Command-Line Interface<2>.
Examples: Examples<8>.
Supported tar formats
Unicode issues

Extraction filters

Default named filters
Filter errors
Hints for further verification
Supporting older Python versions
Stateful extraction filter example

Command-Line Interface

Command-line options: Command-line options<2>.

File Formats

csv — CSV File Reading and Writing
configparser — Configuration file parser
netrc — netrc file processing
plistlib — Generate and parse Apple .plist files: plistlib — Generate and parse Apple plist files.

csv — CSV File Reading and Writing

Module Contents: Module Contents<3>.
Dialects and Formatting Parameters
Reader Objects
Writer Objects
Examples: Examples<9>.

configparser — Configuration file parser

Quick Start
Supported Datatypes
Fallback Values
Supported INI File Structure
Interpolation of values
Mapping Protocol Access
Customizing Parser Behaviour
Legacy API Examples
ConfigParser Objects
RawConfigParser Objects
Exceptions: Exceptions<7>.

netrc — netrc file processing

netrc Objects

plistlib — Generate and parse Apple .plist files

Examples: Examples<10>.

Cryptographic Services

hashlib — Secure hashes and message digests
hmac — Keyed-Hashing for Message Authentication
secrets — Generate secure random numbers for managing secrets

hashlib — Secure hashes and message digests

Hash algorithms
SHAKE variable length digests
Key derivation
BLAKE2

BLAKE2

Creating hash objects
Constants: Constants<5>.
Examples: Examples<11>.
Credits

Examples

Simple hashing
Using different digest sizes
Keyed hashing
Randomized hashing
Personalization
Tree mode

secrets — Generate secure random numbers for managing secrets

Random numbers
Generating tokens
Other functions
Recipes and best practices

Generating tokens

How many bytes should tokens use?

Generic Operating System Services

os — Miscellaneous operating system interfaces
io — Core tools for working with streams
time — Time access and conversions
argparse — Parser for command-line options, arguments and sub-commands: argparse — Parser for command-line options arguments and sub-commands.
getopt — C-style parser for command line options
logging — Logging facility for Python
logging.config — Logging configuration: logging config — Logging configuration.
logging.handlers — Logging handlers: logging handlers — Logging handlers.
getpass — Portable password input
curses — Terminal handling for character-cell displays
curses.textpad — Text input widget for curses programs: curses textpad — Text input widget for curses programs.
curses.ascii — Utilities for ASCII characters: curses ascii — Utilities for ASCII characters.
curses.panel — A panel stack extension for curses: curses panel — A panel stack extension for curses.
platform — Access to underlying platform’s identifying data
errno — Standard errno system symbols
ctypes — A foreign function library for Python

os — Miscellaneous operating system interfaces

File Names, Command Line Arguments, and Environment Variables: File Names Command Line Arguments and Environment Variables.
Python UTF-8 Mode
Process Parameters
File Object Creation
File Descriptor Operations
Files and Directories
Process Management
Interface to the scheduler
Miscellaneous System Information
Random numbers: Random numbers<2>.

File Descriptor Operations

Querying the size of a terminal
Inheritance of File Descriptors

Files and Directories

Linux extended attributes

io — Core tools for working with streams

Overview: Overview<2>.
Text Encoding
High-level Module Interface
Class hierarchy
Performance: Performance<3>.

Overview

Text I/O
Binary I/O
Raw I/O

Text Encoding

Opt-in EncodingWarning

Class hierarchy

I/O Base Classes
Raw File I/O
Buffered Streams
Text I/O: Text I/O<2>.

Performance

Binary I/O: Binary I/O<2>.
Text I/O: Text I/O<3>.
Multi-threading: Multi-threading<3>.
Reentrancy

time — Time access and conversions

Functions: Functions<4>.
Clock ID Constants
Timezone Constants

argparse — Parser for command-line options, arguments and sub-commands

Example: Example<7>.
ArgumentParser objects
The add_argument() method: The add_argument method.
The parse_args() method: The parse_args method.
Other utilities
Upgrading optparse code

Example

Creating a parser
Adding arguments
Parsing arguments

ArgumentParser objects

prog
usage
description
epilog
parents
formatter_class
prefix_chars
fromfile_prefix_chars
argument_default
allow_abbrev
conflict_handler
add_help
exit_on_error

The add_argument() method

name or flags
action
nargs
const
default
type
choices
required
help
metavar
dest
Action classes

The parse_args() method

Option value syntax
Invalid arguments
Arguments containing -
Argument abbreviations (prefix matching): Argument abbreviations prefix matching.
Beyond sys.argv: Beyond sys argv.
The Namespace object

Other utilities

Sub-commands
FileType objects
Argument groups
Mutual exclusion
Parser defaults
Printing help
Partial parsing
Customizing file parsing
Exiting methods
Intermixed parsing

logging — Logging facility for Python

Logger Objects
Logging Levels
Handler Objects
Formatter Objects
Filter Objects
LogRecord Objects
LogRecord attributes
LoggerAdapter Objects
Thread Safety
Module-Level Functions
Module-Level Attributes
Integration with the warnings module

logging.config — Logging configuration

Configuration functions
Security considerations
Configuration dictionary schema
Configuration file format

Configuration dictionary schema

Dictionary Schema Details
Incremental Configuration
Object connections
User-defined objects
Handler configuration order
Access to external objects
Access to internal objects
Import resolution and custom importers

logging.handlers — Logging handlers

StreamHandler
FileHandler
NullHandler
WatchedFileHandler
BaseRotatingHandler
RotatingFileHandler
TimedRotatingFileHandler
SocketHandler
DatagramHandler
SysLogHandler
NTEventLogHandler
SMTPHandler
MemoryHandler
HTTPHandler
QueueHandler
QueueListener

curses — Terminal handling for character-cell displays

Functions: Functions<5>.
Window Objects
Constants: Constants<6>.

curses.textpad — Text input widget for curses programs

Textbox objects

curses.panel — A panel stack extension for curses

Functions: Functions<6>.
Panel Objects

platform — Access to underlying platform’s identifying data

Cross Platform
Java Platform
Windows Platform
macOS Platform
Unix Platforms
Linux Platforms

ctypes — A foreign function library for Python

ctypes tutorial
ctypes reference

ctypes tutorial

Loading dynamic link libraries
Accessing functions from loaded dlls
Calling functions
Fundamental data types
Calling functions, continued: Calling functions continued.
Calling variadic functions
Calling functions with your own custom data types
Specifying the required argument types (function prototypes): Specifying the required argument types function prototypes.
Return types
Passing pointers (or; passing parameters by reference): Passing pointers or passing parameters by reference.
Structures and unions
Structure/union alignment and byte order
Bit fields in structures and unions
Arrays
Pointers
Type conversions
Incomplete Types
Callback functions
Accessing values exported from dlls
Surprises
Variable-sized data types

ctypes reference

Finding shared libraries
Loading shared libraries
Foreign functions
Function prototypes
Utility functions
Data types
Fundamental data types: Fundamental data types<2>.
Structured data types
Arrays and pointers

Concurrent Execution

threading — Thread-based parallelism
multiprocessing — Process-based parallelism
multiprocessing.shared_memory — Shared memory for direct access across processes: multiprocessing shared_memory — Shared memory for direct access across processes.
The concurrent package
concurrent.futures — Launching parallel tasks: concurrent futures — Launching parallel tasks.
subprocess — Subprocess management
sched — Event scheduler
queue — A synchronized queue class
contextvars — Context Variables
_thread — Low-level threading API

threading — Thread-based parallelism

Thread-Local Data
Thread Objects
Lock Objects
RLock Objects
Condition Objects
Semaphore Objects
Event Objects
Timer Objects
Barrier Objects
Using locks, conditions, and semaphores in the with statement: Using locks conditions and semaphores in the with statement.

Semaphore Objects

Semaphore Example

multiprocessing — Process-based parallelism

Introduction: Introduction<7>.
Reference: Reference<2>.
Programming guidelines
Examples: Examples<12>.

Introduction

The Process class
Contexts and start methods
Exchanging objects between processes
Synchronization between processes
Sharing state between processes
Using a pool of workers

Reference

Process and exceptions
Pipes and Queues
Miscellaneous: Miscellaneous<3>.
Connection Objects
Synchronization primitives
Shared ctypes Objects
Managers
Proxy Objects
Process Pools
Listeners and Clients
Authentication keys
Logging: Logging<2>.
The multiprocessing.dummy module: The multiprocessing dummy module.

Shared ctypes Objects

The multiprocessing.sharedctypes module: The multiprocessing sharedctypes module.

Managers

Customized managers
Using a remote manager

Proxy Objects

Cleanup

Listeners and Clients

Address Formats

Programming guidelines

All start methods
The spawn and forkserver start methods

concurrent.futures — Launching parallel tasks

Executor Objects
ThreadPoolExecutor
ProcessPoolExecutor
Future Objects
Module Functions
Exception classes

ThreadPoolExecutor

ThreadPoolExecutor Example

ProcessPoolExecutor

ProcessPoolExecutor Example

subprocess — Subprocess management

Using the subprocess Module
Security Considerations
Popen Objects
Windows Popen Helpers
Older high-level API
Replacing Older Functions with the subprocess Module
Legacy Shell Invocation Functions
Notes

Using the subprocess Module

Frequently Used Arguments
Popen Constructor
Exceptions: Exceptions<8>.

Windows Popen Helpers

Windows Constants

Replacing Older Functions with the subprocess Module

Replacing /bin/sh shell command substitution
Replacing shell pipeline
Replacing os.system(): Replacing os system.
Replacing the os.spawn family: Replacing the os spawn family.
Replacing os.popen(), os.popen2(), os.popen3(): Replacing os popen os popen2 os popen3.
Replacing functions from the popen2 module

Notes

Converting an argument sequence to a string on Windows

sched — Event scheduler

Scheduler Objects

queue — A synchronized queue class

Queue Objects
SimpleQueue Objects

contextvars — Context Variables

Context Variables
Manual Context Management
asyncio support

Networking and Interprocess Communication

asyncio — Asynchronous I/O
socket — Low-level networking interface
ssl — TLS/SSL wrapper for socket objects
select — Waiting for I/O completion
selectors — High-level I/O multiplexing
signal — Set handlers for asynchronous events
mmap — Memory-mapped file support

asyncio — Asynchronous I/O

Coroutines and Tasks
Streams
Synchronization Primitives
Subprocesses
Queues
Exceptions: Exceptions<10>.
Event Loop
Futures
Transports and Protocols
Policies
Platform Support
High-level API Index
Low-level API Index
Developing with asyncio

Coroutines and Tasks

Coroutines: Coroutines<3>.
Awaitables
Running an asyncio Program
Creating Tasks
Sleeping
Running Tasks Concurrently
Shielding From Cancellation
Timeouts
Waiting Primitives
Running in Threads
Scheduling From Other Threads
Introspection
Task Object
Generator-based Coroutines

Streams

StreamReader
StreamWriter
Examples: Examples<13>.

Examples

TCP echo client using streams
TCP echo server using streams
Get HTTP headers
Register an open socket to wait for data using streams

Synchronization Primitives

Lock
Event
Condition
Semaphore
BoundedSemaphore

Subprocesses

Creating Subprocesses
Constants: Constants<7>.
Interacting with Subprocesses

Interacting with Subprocesses

Subprocess and Threads
Examples: Examples<14>.

Queues

Queue
Priority Queue
LIFO Queue
Exceptions: Exceptions<9>.
Examples: Examples<15>.

Event Loop

Event Loop Methods
Callback Handles
Server Objects
Event Loop Implementations
Examples: Examples<16>.

Event Loop Methods

Running and stopping the loop
Scheduling callbacks
Scheduling delayed callbacks
Creating Futures and Tasks
Opening network connections
Creating network servers
Transferring files
TLS Upgrade
Watching file descriptors
Working with socket objects directly
DNS
Working with pipes
Unix signals
Executing code in thread or process pools
Error Handling API
Enabling debug mode
Running Subprocesses

Examples

Hello World with call_soon(): Hello World with call_soon.
Display the current date with call_later(): Display the current date with call_later.
Watch a file descriptor for read events
Set signal handlers for SIGINT and SIGTERM

Futures

Future Functions
Future Object

Transports and Protocols

Transports
Protocols
Examples: Examples<17>.

Transports

Transports Hierarchy
Base Transport
Read-only Transports
Write-only Transports
Datagram Transports
Subprocess Transports

Protocols

Base Protocols
Base Protocol
Streaming Protocols
Buffered Streaming Protocols
Datagram Protocols
Subprocess Protocols

Examples

TCP Echo Server
TCP Echo Client
UDP Echo Server
UDP Echo Client
Connecting Existing Sockets
loop.subprocess_exec() and SubprocessProtocol: loop subprocess_exec and SubprocessProtocol.

Policies

Getting and Setting the Policy
Policy Objects
Process Watchers
Custom Policies

Platform Support

All Platforms
Windows: Windows<59>.
macOS: macOS<35>.

Windows

Subprocess Support on Windows

High-level API Index

Tasks
Queues: Queues<2>.
Subprocesses: Subprocesses<2>.
Streams: Streams<2>.
Synchronization
Exceptions: Exceptions<11>.

Low-level API Index

Obtaining the Event Loop
Event Loop Methods: Event Loop Methods<2>.
Transports: Transports<2>.
Protocols: Protocols<2>.
Event Loop Policies

Developing with asyncio

Debug Mode
Concurrency and Multithreading
Running Blocking Code
Logging: Logging<3>.
Detect never-awaited coroutines
Detect never-retrieved exceptions

socket — Low-level networking interface

Socket families
Module contents
Socket Objects
Notes on socket timeouts
Example: Example<8>.

Module contents

Exceptions: Exceptions<12>.
Constants: Constants<8>.
Functions: Functions<7>.

Functions

Creating sockets
Other functions: Other functions<2>.

Notes on socket timeouts

Timeouts and the connect method
Timeouts and the accept method

ssl — TLS/SSL wrapper for socket objects

Functions, Constants, and Exceptions: Functions Constants and Exceptions.
SSL Sockets
SSL Contexts
Certificates
Examples: Examples<18>.
Notes on non-blocking sockets
Memory BIO Support: Memory BIO Support<2>.
SSL session
Security considerations: Security considerations<2>.
TLS 1.3: TLS 1 3.

Functions, Constants, and Exceptions

Socket creation
Context creation
Exceptions: Exceptions<13>.
Random generation
Certificate handling
Constants: Constants<9>.

Certificates

Certificate chains
CA certificates
Combined key and certificate
Self-signed certificates

Examples

Testing for SSL support
Client-side operation
Server-side operation

Security considerations

Best defaults
Manual settings
Multi-processing

Manual settings

Verifying certificates
Protocol versions
Cipher selection

select — Waiting for I/O completion

/dev/poll Polling Objects
Edge and Level Trigger Polling (epoll) Objects: Edge and Level Trigger Polling epoll Objects.
Polling Objects
Kqueue Objects
Kevent Objects

selectors — High-level I/O multiplexing

Introduction: Introduction<8>.
Classes: Classes<3>.
Examples: Examples<19>.

signal — Set handlers for asynchronous events

General rules
Module contents: Module contents<2>.
Example: Example<9>.
Note on SIGPIPE
Note on Signal Handlers and Exceptions

General rules

Execution of Python signal handlers
Signals and threads

mmap — Memory-mapped file support

MADV_* Constants
MAP_* Constants

Internet Data Handling

email — An email and MIME handling package
json — JSON encoder and decoder
mailbox — Manipulate mailboxes in various formats
mimetypes — Map filenames to MIME types
base64 — Base16, Base32, Base64, Base85 Data Encodings: base64 — Base16 Base32 Base64 Base85 Data Encodings.
binhex — Encode and decode binhex4 files
binascii — Convert between binary and ASCII
quopri — Encode and decode MIME quoted-printable data

email — An email and MIME handling package

email.message; Representing an email message: email message Representing an email message.
email.parser; Parsing email messages: email parser Parsing email messages.
email.generator; Generating MIME documents: email generator Generating MIME documents.
email.policy; Policy Objects: email policy Policy Objects.
email.errors; Exception and Defect classes: email errors Exception and Defect classes.
email.headerregistry; Custom Header Objects: email headerregistry Custom Header Objects.
email.contentmanager; Managing MIME Content: email contentmanager Managing MIME Content.
email; Examples: email Examples.
email.message.Message; Representing an email message using the compat32 API: email message Message Representing an email message using the compat32 API.
email.mime; Creating email and MIME objects from scratch: email mime Creating email and MIME objects from scratch.
email.header; Internationalized headers: email header Internationalized headers.
email.charset; Representing character sets: email charset Representing character sets.
email.encoders; Encoders: email encoders Encoders.
email.utils; Miscellaneous utilities: email utils Miscellaneous utilities.
email.iterators; Iterators: email iterators Iterators.

email.parser: Parsing email messages

FeedParser API
Parser API
Additional notes

email.contentmanager: Managing MIME Content

Content Manager Instances

json — JSON encoder and decoder

Basic Usage
Encoders and Decoders
Exceptions: Exceptions<14>.
Standard Compliance and Interoperability
Command Line Interface: Command Line Interface<2>.

Standard Compliance and Interoperability

Character Encodings
Infinite and NaN Number Values
Repeated Names Within an Object
Top-level Non-Object, Non-Array Values: Top-level Non-Object Non-Array Values.
Implementation Limitations

Command Line Interface

Command line options: Command line options<2>.

mailbox — Manipulate mailboxes in various formats

Mailbox objects
Message objects
Exceptions: Exceptions<15>.
Examples: Examples<20>.

Mailbox objects

Maildir
mbox
MH
Babyl
MMDF

Message objects

MaildirMessage
mboxMessage
MHMessage
BabylMessage
MMDFMessage

mimetypes — Map filenames to MIME types

MimeTypes Objects

base64 — Base16, Base32, Base64, Base85 Data Encodings

Security Considerations: Security Considerations<2>.

binhex — Encode and decode binhex4 files

Notes: Notes<2>.

Structured Markup Processing Tools

html — HyperText Markup Language support
html.parser — Simple HTML and XHTML parser: html parser — Simple HTML and XHTML parser.
html.entities — Definitions of HTML general entities: html entities — Definitions of HTML general entities.
XML Processing Modules
xml.etree.ElementTree — The ElementTree XML API: xml etree ElementTree — The ElementTree XML API.
xml.dom — The Document Object Model API: xml dom — The Document Object Model API.
xml.dom.minidom — Minimal DOM implementation: xml dom minidom — Minimal DOM implementation.
xml.dom.pulldom — Support for building partial DOM trees: xml dom pulldom — Support for building partial DOM trees.
xml.sax — Support for SAX2 parsers: xml sax — Support for SAX2 parsers.
xml.sax.handler — Base classes for SAX handlers: xml sax handler — Base classes for SAX handlers.
xml.sax.saxutils — SAX Utilities: xml sax saxutils — SAX Utilities.
xml.sax.xmlreader — Interface for XML parsers: xml sax xmlreader — Interface for XML parsers.
xml.parsers.expat — Fast XML parsing using Expat: xml parsers expat — Fast XML parsing using Expat.

html.parser — Simple HTML and XHTML parser

Example HTML Parser Application
HTMLParser Methods
Examples: Examples<21>.

XML Processing Modules

XML vulnerabilities
The defusedxml Package

xml.etree.ElementTree — The ElementTree XML API

Tutorial: Tutorial<2>.
XPath support
Reference: Reference<3>.
XInclude support
Reference: Reference<4>.

Tutorial

XML tree and elements
Parsing XML
Pull API for non-blocking parsing
Finding interesting elements
Modifying an XML File
Building XML documents
Parsing XML with Namespaces

XPath support

Example: Example<10>.
Supported XPath syntax

Reference

Functions: Functions<8>.

XInclude support

Example: Example<11>.

Reference

Functions: Functions<9>.
Element Objects
ElementTree Objects
QName Objects
TreeBuilder Objects
XMLParser Objects
XMLPullParser Objects
Exceptions: Exceptions<16>.

xml.dom — The Document Object Model API

Module Contents: Module Contents<4>.
Objects in the DOM
Conformance

Objects in the DOM

DOMImplementation Objects
Node Objects
NodeList Objects
DocumentType Objects
Document Objects
Element Objects: Element Objects<2>.
Attr Objects
NamedNodeMap Objects
Comment Objects
Text and CDATASection Objects
ProcessingInstruction Objects
Exceptions: Exceptions<17>.

Conformance

Type Mapping
Accessor Methods

xml.dom.minidom — Minimal DOM implementation

DOM Objects
DOM Example
minidom and the DOM standard

xml.dom.pulldom — Support for building partial DOM trees

DOMEventStream Objects

xml.sax — Support for SAX2 parsers

SAXException Objects

xml.sax.handler — Base classes for SAX handlers

ContentHandler Objects
DTDHandler Objects
EntityResolver Objects
ErrorHandler Objects
LexicalHandler Objects

xml.sax.xmlreader — Interface for XML parsers

XMLReader Objects
IncrementalParser Objects
Locator Objects
InputSource Objects
The Attributes Interface
The AttributesNS Interface

xml.parsers.expat — Fast XML parsing using Expat

XMLParser Objects: XMLParser Objects<2>.
ExpatError Exceptions
Example: Example<12>.
Content Model Descriptions
Expat error constants

Internet Protocols and Support

webbrowser — Convenient web-browser controller
wsgiref — WSGI Utilities and Reference Implementation
urllib — URL handling modules
urllib.request — Extensible library for opening URLs: urllib request — Extensible library for opening URLs.
urllib.response — Response classes used by urllib: urllib response — Response classes used by urllib.
urllib.parse — Parse URLs into components: urllib parse — Parse URLs into components.
urllib.error — Exception classes raised by urllib.request: urllib error — Exception classes raised by urllib request.
urllib.robotparser — Parser for robots.txt: urllib robotparser — Parser for robots txt.
http — HTTP modules
http.client — HTTP protocol client: http client — HTTP protocol client.
ftplib — FTP protocol client
poplib — POP3 protocol client
imaplib — IMAP4 protocol client
smtplib — SMTP protocol client
uuid — UUID objects according to RFC 4122
socketserver — A framework for network servers
http.server — HTTP servers: http server — HTTP servers.
http.cookies — HTTP state management: http cookies — HTTP state management.
http.cookiejar — Cookie handling for HTTP clients: http cookiejar — Cookie handling for HTTP clients.
xmlrpc — XMLRPC server and client modules
xmlrpc.client — XML-RPC client access: xmlrpc client — XML-RPC client access.
xmlrpc.server — Basic XML-RPC servers: xmlrpc server — Basic XML-RPC servers.
ipaddress — IPv4/IPv6 manipulation library

webbrowser — Convenient web-browser controller

Browser Controller Objects

wsgiref — WSGI Utilities and Reference Implementation

wsgiref.util – WSGI environment utilities: wsgiref util – WSGI environment utilities.
wsgiref.headers – WSGI response header tools: wsgiref headers – WSGI response header tools.
wsgiref.simple_server – a simple WSGI HTTP server: wsgiref simple_server – a simple WSGI HTTP server.
wsgiref.validate — WSGI conformance checker: wsgiref validate — WSGI conformance checker.
wsgiref.handlers – server/gateway base classes: wsgiref handlers – server/gateway base classes.
Examples: Examples<22>.

urllib.request — Extensible library for opening URLs

Request Objects
OpenerDirector Objects
BaseHandler Objects
HTTPRedirectHandler Objects
HTTPCookieProcessor Objects
ProxyHandler Objects
HTTPPasswordMgr Objects
HTTPPasswordMgrWithPriorAuth Objects
AbstractBasicAuthHandler Objects
HTTPBasicAuthHandler Objects
ProxyBasicAuthHandler Objects
AbstractDigestAuthHandler Objects
HTTPDigestAuthHandler Objects
ProxyDigestAuthHandler Objects
HTTPHandler Objects
HTTPSHandler Objects
FileHandler Objects
DataHandler Objects
FTPHandler Objects
CacheFTPHandler Objects
UnknownHandler Objects
HTTPErrorProcessor Objects
Examples: Examples<23>.
Legacy interface
urllib.request Restrictions: urllib request Restrictions.

urllib.parse — Parse URLs into components

URL Parsing
URL parsing security
Parsing ASCII Encoded Bytes
Structured Parse Results
URL Quoting

http — HTTP modules

HTTP status codes

http.client — HTTP protocol client

HTTPConnection Objects
HTTPResponse Objects
Examples: Examples<24>.
HTTPMessage Objects

ftplib — FTP protocol client

FTP Objects
FTP_TLS Objects

poplib — POP3 protocol client

POP3 Objects
POP3 Example

imaplib — IMAP4 protocol client

IMAP4 Objects
IMAP4 Example

smtplib — SMTP protocol client

SMTP Objects
SMTP Example

uuid — UUID objects according to RFC 4122

Example: Example<13>.

socketserver — A framework for network servers

Server Creation Notes
Server Objects: Server Objects<2>.
Request Handler Objects
Examples: Examples<25>.

Examples

socketserver.TCPServer Example: socketserver TCPServer Example.
socketserver.UDPServer Example: socketserver UDPServer Example.
Asynchronous Mixins

http.server — HTTP servers

Security Considerations: Security Considerations<3>.

http.cookies — HTTP state management

Cookie Objects
Morsel Objects
Example: Example<14>.

http.cookiejar — Cookie handling for HTTP clients

CookieJar and FileCookieJar Objects
FileCookieJar subclasses and co-operation with web browsers
CookiePolicy Objects
DefaultCookiePolicy Objects
Cookie Objects: Cookie Objects<2>.
Examples: Examples<26>.

xmlrpc.client — XML-RPC client access

ServerProxy Objects
DateTime Objects
Binary Objects
Fault Objects
ProtocolError Objects
MultiCall Objects
Convenience Functions
Example of Client Usage
Example of Client and Server Usage

xmlrpc.server — Basic XML-RPC servers

SimpleXMLRPCServer Objects
CGIXMLRPCRequestHandler
Documenting XMLRPC server
DocXMLRPCServer Objects
DocCGIXMLRPCRequestHandler

SimpleXMLRPCServer Objects

SimpleXMLRPCServer Example

ipaddress — IPv4/IPv6 manipulation library

Convenience factory functions
IP Addresses
IP Network definitions
Interface objects
Other Module Level Functions
Custom Exceptions

IP Addresses

Address objects
Conversion to Strings and Integers
Operators: Operators<3>.

Operators

Comparison operators
Arithmetic operators

IP Network definitions

Prefix, net mask and host mask: Prefix net mask and host mask.
Network objects
Operators: Operators<4>.

Operators

Logical operators
Iteration: Iteration<2>.
Networks as containers of addresses

Interface objects

Operators: Operators<5>.

Operators

Logical operators: Logical operators<2>.

Multimedia Services

wave — Read and write WAV files
colorsys — Conversions between color systems

wave — Read and write WAV files

Wave_read Objects
Wave_write Objects

Internationalization

gettext — Multilingual internationalization services
locale — Internationalization services

gettext — Multilingual internationalization services

GNU gettext API
Class-based API
Internationalizing your programs and modules
Acknowledgements: Acknowledgements<9>.

Class-based API

The NullTranslations class
The GNUTranslations class
Solaris message catalog support
The Catalog constructor

Internationalizing your programs and modules

Localizing your module
Localizing your application
Changing languages on the fly
Deferred translations

locale — Internationalization services

Background, details, hints, tips and caveats: Background details hints tips and caveats.
For extension writers and programs that embed Python
Access to message catalogs

Program Frameworks

turtle — Turtle graphics
cmd — Support for line-oriented command interpreters
shlex — Simple lexical analysis

turtle — Turtle graphics

Introduction: Introduction<9>.
Overview of available Turtle and Screen methods
Methods of RawTurtle/Turtle and corresponding functions
Methods of TurtleScreen/Screen and corresponding functions
Public classes
Help and configuration
turtledemo — Demo scripts
Changes since Python 2.6: Changes since Python 2 6.
Changes since Python 3.0: Changes since Python 3 0.

Overview of available Turtle and Screen methods

Turtle methods
Methods of TurtleScreen/Screen

Methods of RawTurtle/Turtle and corresponding functions

Turtle motion
Tell Turtle’s state
Settings for measurement
Pen control
Turtle state
Using events
Special Turtle methods
Compound shapes

Pen control

Drawing state
Color control
Filling
More drawing control

Turtle state

Visibility
Appearance

Methods of TurtleScreen/Screen and corresponding functions

Window control
Animation control
Using screen events
Input methods
Settings and special methods
Methods specific to Screen, not inherited from TurtleScreen: Methods specific to Screen not inherited from TurtleScreen.

Help and configuration

How to use help
Translation of docstrings into different languages
How to configure Screen and Turtles

cmd — Support for line-oriented command interpreters

Cmd Objects
Cmd Example

shlex — Simple lexical analysis

shlex Objects
Parsing Rules
Improved Compatibility with Shells

Graphical User Interfaces with Tk

tkinter — Python interface to Tcl/Tk
tkinter.colorchooser — Color choosing dialog: tkinter colorchooser — Color choosing dialog.
tkinter.font — Tkinter font wrapper: tkinter font — Tkinter font wrapper.
Tkinter Dialogs
tkinter.messagebox — Tkinter message prompts: tkinter messagebox — Tkinter message prompts.
tkinter.scrolledtext — Scrolled Text Widget: tkinter scrolledtext — Scrolled Text Widget.
tkinter.dnd — Drag and drop support: tkinter dnd — Drag and drop support.
tkinter.ttk — Tk themed widgets: tkinter ttk — Tk themed widgets.
tkinter.tix — Extension widgets for Tk: tkinter tix — Extension widgets for Tk.
IDLE: IDLE<55>.

tkinter — Python interface to Tcl/Tk

Architecture
Tkinter Modules
Tkinter Life Preserver
Threading model
Handy Reference
File Handlers

Tkinter Life Preserver

A Hello World Program
Important Tk Concepts
Understanding How Tkinter Wraps Tcl/Tk
How do I…? What option does…?
Navigating the Tcl/Tk Reference Manual

Handy Reference

Setting Options
The Packer
Packer Options
Coupling Widget Variables
The Window Manager
Tk Option Data Types
Bindings and Events
The index Parameter
Images

Tkinter Dialogs

tkinter.simpledialog — Standard Tkinter input dialogs: tkinter simpledialog — Standard Tkinter input dialogs.
tkinter.filedialog — File selection dialogs: tkinter filedialog — File selection dialogs.
tkinter.commondialog — Dialog window templates: tkinter commondialog — Dialog window templates.

tkinter.filedialog — File selection dialogs

Native Load/Save Dialogs

tkinter.ttk — Tk themed widgets

Using Ttk
Ttk Widgets
Widget
Combobox
Spinbox
Notebook
Progressbar
Separator
Sizegrip
Treeview
Ttk Styling

Widget

Standard Options
Scrollable Widget Options
Label Options
Compatibility Options
Widget States
ttk.Widget: ttk Widget.

Combobox

Options
Virtual events
ttk.Combobox: ttk Combobox.

Spinbox

Options: Options<2>.
Virtual events: Virtual events<2>.
ttk.Spinbox: ttk Spinbox.

Notebook

Options: Options<3>.
Tab Options
Tab Identifiers
Virtual Events
ttk.Notebook: ttk Notebook.

Progressbar

Options: Options<4>.
ttk.Progressbar: ttk Progressbar.

Separator

Options: Options<5>.

Sizegrip

Platform-specific notes
Bugs

Treeview

Options: Options<6>.
Item Options
Tag Options
Column Identifiers
Virtual Events: Virtual Events<2>.
ttk.Treeview: ttk Treeview.

Ttk Styling

Layouts

tkinter.tix — Extension widgets for Tk

Using Tix
Tix Widgets
Tix Commands

Tix Widgets

Basic Widgets
File Selectors
Hierarchical ListBox
Tabular ListBox
Manager Widgets
Image Types
Miscellaneous Widgets
Form Geometry Manager

IDLE

Menus
Editing and Navigation
Startup and Code Execution
Help and Preferences
idlelib

Menus

File menu (Shell and Editor): File menu Shell and Editor.
Edit menu (Shell and Editor): Edit menu Shell and Editor.
Format menu (Editor window only): Format menu Editor window only.
Run menu (Editor window only): Run menu Editor window only.
Shell menu (Shell window only): Shell menu Shell window only.
Debug menu (Shell window only): Debug menu Shell window only.
Options menu (Shell and Editor): Options menu Shell and Editor.
Window menu (Shell and Editor): Window menu Shell and Editor.
Help menu (Shell and Editor): Help menu Shell and Editor.
Context menus

Editing and Navigation

Editor windows
Key bindings
Automatic indentation
Search and Replace
Completions
Calltips
Code Context
Shell window
Text colors

Startup and Code Execution

Command line usage
Startup failure
Running user code
User output in Shell
Developing tkinter applications
Running without a subprocess

Help and Preferences

Help sources
Setting preferences
IDLE on macOS
Extensions

Development Tools

typing — Support for type hints
pydoc — Documentation generator and online help system
Python Development Mode
Effects of the Python Development Mode
ResourceWarning Example
Bad file descriptor error example
doctest — Test interactive Python examples
unittest — Unit testing framework
unittest.mock — mock object library: unittest mock — mock object library.
unittest.mock — getting started: unittest mock — getting started.
2to3 — Automated Python 2 to 3 code translation
test — Regression tests package for Python
test.support — Utilities for the Python test suite: test support — Utilities for the Python test suite.
test.support.socket_helper — Utilities for socket tests: test support socket_helper — Utilities for socket tests.
test.support.script_helper — Utilities for the Python execution tests: test support script_helper — Utilities for the Python execution tests.
test.support.bytecode_helper — Support tools for testing correct bytecode generation: test support bytecode_helper — Support tools for testing correct bytecode generation.
test.support.threading_helper — Utilities for threading tests: test support threading_helper — Utilities for threading tests.
test.support.os_helper — Utilities for os tests: test support os_helper — Utilities for os tests.
test.support.import_helper — Utilities for import tests: test support import_helper — Utilities for import tests.
test.support.warnings_helper — Utilities for warnings tests: test support warnings_helper — Utilities for warnings tests.

typing — Support for type hints

Relevant PEPs
Type aliases
NewType
Callable
Generics
User-defined generic types
The Any type
Nominal vs structural subtyping
Module contents: Module contents<3>.

Module contents

Special typing primitives
Generic concrete collections
Abstract Base Classes
Protocols: Protocols<3>.
Functions and decorators
Introspection helpers
Constant

Special typing primitives

Special types
Special forms
Building generic types
Other special directives

Generic concrete collections

Corresponding to built-in types
Corresponding to types in collections
Other concrete types

Abstract Base Classes

Corresponding to collections in collections.abc: Corresponding to collections in collections abc.
Corresponding to other types in collections.abc: Corresponding to other types in collections abc.
Asynchronous programming
Context manager types

doctest — Test interactive Python examples

Simple Usage; Checking Examples in Docstrings: Simple Usage Checking Examples in Docstrings.
Simple Usage; Checking Examples in a Text File: Simple Usage Checking Examples in a Text File.
How It Works
Basic API
Unittest API
Advanced API
Debugging
Soapbox

How It Works

Which Docstrings Are Examined?
How are Docstring Examples Recognized?
What’s the Execution Context?
What About Exceptions?
Option Flags
Directives
Warnings: Warnings<2>.

Advanced API

DocTest Objects
Example Objects
DocTestFinder objects
DocTestParser objects
DocTestRunner objects
OutputChecker objects

unittest — Unit testing framework

Basic example
Command-Line Interface: Command-Line Interface<3>.
Test Discovery
Organizing test code
Re-using old test code
Skipping tests and expected failures
Distinguishing test iterations using subtests
Classes and functions
Class and Module Fixtures
Signal Handling

Command-Line Interface

Command-line options: Command-line options<3>.

Classes and functions

Test cases
Grouping tests
Loading and running tests

Test cases

Deprecated aliases

Loading and running tests

load_tests Protocol

Class and Module Fixtures

setUpClass and tearDownClass
setUpModule and tearDownModule

unittest.mock — mock object library

Quick Guide
The Mock Class
The patchers
MagicMock and magic method support
Helpers

The Mock Class

Calling
Deleting Attributes
Mock names and the name attribute
Attaching Mocks as Attributes

The patchers

patch
patch.object: patch object.
patch.dict: patch dict.
patch.multiple: patch multiple.
patch methods; start and stop: patch methods start and stop.
patch builtins
TEST_PREFIX
Nesting Patch Decorators
Where to patch
Patching Descriptors and Proxy Objects

MagicMock and magic method support

Mocking Magic Methods
Magic Mock

Helpers

sentinel
DEFAULT
call
create_autospec
ANY
FILTER_DIR
mock_open
Autospeccing
Sealing mocks

unittest.mock — getting started

Using Mock
Patch Decorators
Further Examples

Using Mock

Mock Patching Methods
Mock for Method Calls on an Object
Mocking Classes
Naming your mocks
Tracking all Calls
Setting Return Values and Attributes
Raising exceptions with mocks
Side effect functions and iterables
Mocking asynchronous iterators
Mocking asynchronous context manager
Creating a Mock from an Existing Object

Further Examples

Mocking chained calls
Partial mocking
Mocking a Generator Method
Applying the same patch to every test method
Mocking Unbound Methods
Checking multiple calls with mock
Coping with mutable arguments
Nesting Patches
Mocking a dictionary with MagicMock
Mock subclasses and their attributes
Mocking imports with patch.dict: Mocking imports with patch dict.
Tracking order of calls and less verbose call assertions
More complex argument matching

2to3 — Automated Python 2 to 3 code translation

Using 2to3
Fixers
lib2to3 — 2to3’s library

test — Regression tests package for Python

Writing Unit Tests for the test package
Running tests using the command-line interface

Debugging and Profiling

Audit events table
bdb — Debugger framework
faulthandler — Dump the Python traceback
pdb — The Python Debugger
The Python Profilers
timeit — Measure execution time of small code snippets
trace — Trace or track Python statement execution
tracemalloc — Trace memory allocations

faulthandler — Dump the Python traceback

Dumping the traceback
Fault handler state
Dumping the tracebacks after a timeout
Dumping the traceback on a user signal
Issue with file descriptors
Example: Example<15>.

pdb — The Python Debugger

Debugger Commands

The Python Profilers

Introduction to the profilers
Instant User’s Manual
profile and cProfile Module Reference
The Stats Class
What Is Deterministic Profiling?
Limitations
Calibration
Using a custom timer

timeit — Measure execution time of small code snippets

Basic Examples: Basic Examples<2>.
Python Interface
Command-Line Interface: Command-Line Interface<4>.
Examples: Examples<27>.

trace — Trace or track Python statement execution

Command-Line Usage
Programmatic Interface

Command-Line Usage

Main options
Modifiers
Filters

tracemalloc — Trace memory allocations

Examples: Examples<28>.
API

Examples

Display the top 10
Compute differences
Get the traceback of a memory block
Pretty top

Pretty top

Record the current and peak size of all traced memory blocks

API

Functions: Functions<10>.
DomainFilter
Filter
Frame
Snapshot
Statistic
StatisticDiff
Trace
Traceback

Software Packaging and Distribution

distutils — Building and installing Python modules
ensurepip — Bootstrapping the pip installer
venv — Creation of virtual environments
zipapp — Manage executable Python zip archives

ensurepip — Bootstrapping the pip installer

Command line interface
Module API

venv — Creation of virtual environments

Creating virtual environments
How venvs work
API: API<2>.
An example of extending EnvBuilder

zipapp — Manage executable Python zip archives

Basic Example
Command-Line Interface: Command-Line Interface<5>.
Python API
Examples: Examples<29>.
Specifying the Interpreter
Creating Standalone Applications with zipapp
The Python Zip Application Archive Format

Creating Standalone Applications with zipapp

Making a Windows executable
Caveats

Python Runtime Services

sys — System-specific parameters and functions
sysconfig — Provide access to Python’s configuration information
builtins — Built-in objects
__main__ — Top-level code environment
warnings — Warning control
dataclasses — Data Classes
contextlib — Utilities for with-statement contexts
abc — Abstract Base Classes
atexit — Exit handlers
traceback — Print or retrieve a stack traceback
__future__ — Future statement definitions
gc — Garbage Collector interface
inspect — Inspect live objects
site — Site-specific configuration hook

sysconfig — Provide access to Python’s configuration information

Configuration variables
Installation paths
Other functions: Other functions<3>.
Using sysconfig as a script

__main__ — Top-level code environment

__name__ == '__main__'
__main__.py in Python Packages: __main__ py in Python Packages.
import __main__

__name__ == ’__main__’

What is the “top-level code environment”?
Idiomatic Usage
Packaging Considerations

__main__.py in Python Packages

Idiomatic Usage: Idiomatic Usage<2>.

warnings — Warning control

Warning Categories
The Warnings Filter
Temporarily Suppressing Warnings
Testing Warnings
Updating Code For New Versions of Dependencies
Available Functions
Available Context Managers

The Warnings Filter

Describing Warning Filters
Default Warning Filter
Overriding the default filter

dataclasses — Data Classes

Module contents: Module contents<4>.
Post-init processing
Class variables
Init-only variables
Frozen instances
Inheritance: Inheritance<2>.
Re-ordering of keyword-only parameters in __init__(): Re-ordering of keyword-only parameters in __init__.
Default factory functions
Mutable default values
Descriptor-typed fields

contextlib — Utilities for with-statement contexts

Utilities
Examples and Recipes: Examples and Recipes<2>.
Single use, reusable and reentrant context managers: Single use reusable and reentrant context managers.

Examples and Recipes

Supporting a variable number of context managers
Catching exceptions from __enter__ methods
Cleaning up in an __enter__ implementation
Replacing any use of try-finally and flag variables
Using a context manager as a function decorator

Single use, reusable and reentrant context managers

Reentrant context managers
Reusable context managers

atexit — Exit handlers

atexit Example

traceback — Print or retrieve a stack traceback

TracebackException Objects
StackSummary Objects
FrameSummary Objects
Traceback Examples

inspect — Inspect live objects

Types and members
Retrieving source code
Introspecting callables with the Signature object
Classes and functions: Classes and functions<2>.
The interpreter stack
Fetching attributes statically
Current State of Generators and Coroutines
Code Objects Bit Flags
Command Line Interface: Command Line Interface<3>.

site — Site-specific configuration hook

Readline configuration
Module contents: Module contents<5>.
Command Line Interface: Command Line Interface<4>.

Custom Python Interpreters

code — Interpreter base classes
codeop — Compile Python code

code — Interpreter base classes

Interactive Interpreter Objects
Interactive Console Objects

Importing Modules

zipimport — Import modules from Zip archives
pkgutil — Package extension utility
modulefinder — Find modules used by a script
runpy — Locating and executing Python modules
importlib — The implementation of import
Using importlib.metadata: Using importlib metadata.

zipimport — Import modules from Zip archives

zipimporter Objects
Examples: Examples<30>.

modulefinder — Find modules used by a script

Example usage of ModuleFinder

importlib — The implementation of import

Introduction: Introduction<10>.
Functions: Functions<11>.
importlib.abc – Abstract base classes related to import: importlib abc – Abstract base classes related to import.
importlib.resources – Resources: importlib resources – Resources.
importlib.machinery – Importers and path hooks: importlib machinery – Importers and path hooks.
importlib.util – Utility code for importers: importlib util – Utility code for importers.
Examples: Examples<31>.

Examples

Importing programmatically
Checking if a module can be imported
Importing a source file directly
Implementing lazy imports
Setting up an importer
Approximating importlib.import_module(): Approximating importlib import_module.

Using importlib.metadata

Overview: Overview<3>.
Functional API: Functional API<2>.
Distributions
Extending the search algorithm

Functional API

Entry points
Distribution metadata
Distribution versions
Distribution files
Distribution requirements
Package distributions

Python Language Services

ast — Abstract Syntax Trees
symtable — Access to the compiler’s symbol tables
token — Constants used with Python parse trees
keyword — Testing for Python keywords
tokenize — Tokenizer for Python source
tabnanny — Detection of ambiguous indentation
pyclbr — Python module browser support
py_compile — Compile Python source files
compileall — Byte-compile Python libraries
dis — Disassembler for Python bytecode
pickletools — Tools for pickle developers

ast — Abstract Syntax Trees

Abstract Grammar
Node classes
ast Helpers
Compiler Flags
Command-Line Usage: Command-Line Usage<2>.

Node classes

Literals: Literals<3>.
Variables
Expressions: Expressions<2>.
Statements
Control flow
Pattern matching
Function and class definitions
Async and await

Expressions

Subscripting
Comprehensions

Statements

Imports

symtable — Access to the compiler’s symbol tables

Generating Symbol Tables
Examining Symbol Tables

tokenize — Tokenizer for Python source

Tokenizing Input
Command-Line Usage: Command-Line Usage<3>.
Examples: Examples<32>.

pyclbr — Python module browser support

Function Objects
Class Objects: Class Objects<2>.

py_compile — Compile Python source files

Command-Line Interface: Command-Line Interface<6>.

compileall — Byte-compile Python libraries

Command-line use
Public functions

dis — Disassembler for Python bytecode

Bytecode analysis
Analysis functions
Python Bytecode Instructions
Opcode collections

pickletools — Tools for pickle developers

Command line usage: Command line usage<2>.
Programmatic Interface: Programmatic Interface<2>.

Command line usage

Command line options: Command line options<3>.

MS Windows Specific Services

msvcrt — Useful routines from the MS VC++ runtime
winreg — Windows registry access
winsound — Sound-playing interface for Windows

msvcrt — Useful routines from the MS VC++ runtime

File Operations
Console I/O
Other Functions

winreg — Windows registry access

Functions: Functions<12>.
Constants: Constants<10>.
Registry Handle Objects

Constants

HKEY_* Constants
Access Rights
Value Types

Access Rights

64-bit Specific

Unix Specific Services

posix — The most common POSIX system calls
pwd — The password database
grp — The group database
termios — POSIX style tty control
tty — Terminal control functions
pty — Pseudo-terminal utilities
fcntl — The fcntl and ioctl system calls
resource — Resource usage information
syslog — Unix syslog library routines

posix — The most common POSIX system calls

Large File Support
Notable Module Contents

termios — POSIX style tty control

Example: Example<16>.

pty — Pseudo-terminal utilities

Example: Example<17>.

resource — Resource usage information

Resource Limits
Resource Usage

syslog — Unix syslog library routines

Examples: Examples<33>.

Examples

Simple example

Superseded Modules

aifc — Read and write AIFF and AIFC files
asynchat — Asynchronous socket command/response handler
asyncore — Asynchronous socket handler
audioop — Manipulate raw audio data
cgi — Common Gateway Interface support
cgitb — Traceback manager for CGI scripts
chunk — Read IFF chunked data
crypt — Function to check Unix passwords
imghdr — Determine the type of an image
imp — Access the import internals
mailcap — Mailcap file handling
msilib — Read and write Microsoft Installer files
nis — Interface to Sun’s NIS (Yellow Pages): nis — Interface to Sun’s NIS Yellow Pages.
nntplib — NNTP protocol client
optparse — Parser for command line options
ossaudiodev — Access to OSS-compatible audio devices
pipes — Interface to shell pipelines
smtpd — SMTP Server
sndhdr — Determine type of sound file
spwd — The shadow password database
sunau — Read and write Sun AU files
telnetlib — Telnet client
uu — Encode and decode uuencode files
xdrlib — Encode and decode XDR data

asynchat — Asynchronous socket command/response handler

asynchat Example

asyncore — Asynchronous socket handler

asyncore Example basic HTTP client
asyncore Example basic echo server

cgi — Common Gateway Interface support

Introduction: Introduction<11>.
Using the cgi module
Higher Level Interface
Functions: Functions<13>.
Caring about security
Installing your CGI script on a Unix system
Testing your CGI script
Debugging CGI scripts
Common problems and solutions

crypt — Function to check Unix passwords

Hashing Methods
Module Attributes
Module Functions: Module Functions<2>.
Examples: Examples<34>.

imp — Access the import internals

Examples: Examples<35>.

msilib — Read and write Microsoft Installer files

Database Objects
View Objects
Summary Information Objects
Record Objects
Errors
CAB Objects
Directory Objects
Features: Features<3>.
GUI classes
Precomputed tables

nntplib — NNTP protocol client

NNTP Objects
Utility functions: Utility functions<2>.

NNTP Objects

Attributes
Methods: Methods<3>.

optparse — Parser for command line options

Background
Tutorial: Tutorial<3>.
Reference Guide
Option Callbacks
Extending optparse

Background

Terminology
What are options for?
What are positional arguments for?

Tutorial

Understanding option actions
The store action
Handling boolean (flag) options: Handling boolean flag options.
Other actions
Default values
Generating help
Printing a version string
How optparse handles errors
Putting it all together

Generating help

Grouping Options

Reference Guide

Creating the parser
Populating the parser
Defining options
Option attributes
Standard option actions
Standard option types
Parsing arguments: Parsing arguments<2>.
Querying and manipulating your option parser
Conflicts between options
Cleanup: Cleanup<2>.
Other methods

Option Callbacks

Defining a callback option
How callbacks are called
Raising errors in a callback
Callback example 1; trivial callback: Callback example 1 trivial callback.
Callback example 2; check option order: Callback example 2 check option order.
Callback example 3; check option order (generalized): Callback example 3 check option order generalized.
Callback example 4; check arbitrary condition: Callback example 4 check arbitrary condition.
Callback example 5; fixed arguments: Callback example 5 fixed arguments.
Callback example 6; variable arguments: Callback example 6 variable arguments.

Extending optparse

Adding new types
Adding new actions

ossaudiodev — Access to OSS-compatible audio devices

Audio Device Objects
Mixer Device Objects

pipes — Interface to shell pipelines

Template Objects

smtpd — SMTP Server

SMTPServer Objects
DebuggingServer Objects
PureProxy Objects
MailmanProxy Objects
SMTPChannel Objects

sunau — Read and write Sun AU files

AU_read Objects
AU_write Objects

telnetlib — Telnet client

Telnet Objects
Telnet Example

xdrlib — Encode and decode XDR data

Packer Objects
Unpacker Objects
Exceptions: Exceptions<18>.

Extending and Embedding the Python Interpreter

Recommended third party tools
Creating extensions without third party tools
Embedding the CPython runtime in a larger application

Creating extensions without third party tools

Extending Python with C or C++
Defining Extension Types; Tutorial: Defining Extension Types Tutorial.
Defining Extension Types; Assorted Topics: Defining Extension Types Assorted Topics.
Building C and C++ Extensions
Building C and C++ Extensions on Windows

Extending Python with C or C++

A Simple Example
Intermezzo; Errors and Exceptions: Intermezzo Errors and Exceptions.
Back to the Example
The Module’s Method Table and Initialization Function
Compilation and Linkage
Calling Python Functions from C
Extracting Parameters in Extension Functions
Keyword Parameters for Extension Functions
Building Arbitrary Values
Reference Counts
Writing Extensions in C++
Providing a C API for an Extension Module

Reference Counts

Reference Counting in Python
Ownership Rules
Thin Ice
NULL Pointers

Defining Extension Types: Tutorial

The Basics
Adding data and methods to the Basic example
Providing finer control over data attributes
Supporting cyclic garbage collection
Subclassing other types

Defining Extension Types: Assorted Topics

Finalization and De-allocation
Object Presentation
Attribute Management
Object Comparison
Abstract Protocol Support
Weak Reference Support
More Suggestions

Attribute Management

Generic Attribute Management
Type-specific Attribute Management

Building C and C++ Extensions

Building C and C++ Extensions with distutils
Distributing your extension modules

Building C and C++ Extensions on Windows

A Cookbook Approach
Differences Between Unix and Windows
Using DLLs in Practice

Embedding the CPython runtime in a larger application

Embedding Python in Another Application

Embedding Python in Another Application

Very High Level Embedding
Beyond Very High Level Embedding; An overview: Beyond Very High Level Embedding An overview.
Pure Embedding
Extending Embedded Python
Embedding Python in C++
Compiling and Linking under Unix-like systems

Python/C API Reference Manual

Introduction: Introduction<12>.
C API Stability
The Very High Level Layer
Reference Counting
Exception Handling
Utilities: Utilities<2>.
Abstract Objects Layer
Concrete Objects Layer
Initialization, Finalization, and Threads: Initialization Finalization and Threads.
Python Initialization Configuration
Memory Management
Object Implementation Support
API and ABI Versioning

Introduction

Coding standards
Include Files
Useful macros
Objects, Types and Reference Counts: Objects Types and Reference Counts.
Exceptions: Exceptions<19>.
Embedding Python: Embedding Python<2>.
Debugging Builds

Objects, Types and Reference Counts

Reference Counts: Reference Counts<2>.
Types

Reference Counts

Reference Count Details

C API Stability

Stable Application Binary Interface
Platform Considerations
Contents of Limited API

Stable Application Binary Interface

Limited API Scope and Performance
Limited API Caveats

Exception Handling

Printing and clearing
Raising exceptions
Issuing warnings
Querying the error indicator
Signal Handling: Signal Handling<2>.
Exception Classes
Exception Objects
Unicode Exception Objects
Recursion Control
Standard Exceptions
Standard Warning Categories

Utilities

Operating System Utilities
System Functions
Process Control
Importing Modules: Importing Modules<2>.
Data marshalling support
Parsing arguments and building values
String conversion and formatting
Reflection
Codec registry and support functions

Parsing arguments and building values

Parsing arguments: Parsing arguments<3>.
Building values

Parsing arguments

Strings and buffers
Numbers: Numbers<2>.
Other objects
API Functions

Codec registry and support functions

Codec lookup API
Registry API for Unicode encoding error handlers

Abstract Objects Layer

Object Protocol
Call Protocol
Number Protocol
Sequence Protocol
Mapping Protocol
Iterator Protocol
Buffer Protocol
Old Buffer Protocol

Call Protocol

The tp_call Protocol
The Vectorcall Protocol
Object Calling API
Call Support API

The Vectorcall Protocol

Recursion Control: Recursion Control<2>.
Vectorcall Support API

Buffer Protocol

Buffer structure
Buffer request types
Complex arrays
Buffer-related functions

Buffer request types

request-independent fields
readonly, format: readonly format.
shape, strides, suboffsets: shape strides suboffsets.
contiguity requests
compound requests

Complex arrays

NumPy-style; shape and strides: NumPy-style shape and strides.
PIL-style; shape, strides and suboffsets: PIL-style shape strides and suboffsets.

Concrete Objects Layer

Fundamental Objects
Numeric Objects
Sequence Objects
Container Objects
Function Objects: Function Objects<2>.
Other Objects

Fundamental Objects

Type Objects: Type Objects<2>.
The None Object

Type Objects

Creating Heap-Allocated Types

Numeric Objects

Integer Objects
Boolean Objects
Floating Point Objects
Complex Number Objects

Complex Number Objects

Complex Numbers as C Structures
Complex Numbers as Python Objects

Sequence Objects

Bytes Objects: Bytes Objects<2>.
Byte Array Objects
Unicode Objects and Codecs
Tuple Objects
Struct Sequence Objects
List Objects

Byte Array Objects

Type check macros
Direct API functions
Macros

Unicode Objects and Codecs

Unicode Objects
Built-in Codecs
Methods and Slot Functions

Unicode Objects

Unicode Type
Unicode Character Properties
Creating and accessing Unicode strings
Deprecated Py_UNICODE APIs
Locale Encoding
File System Encoding
wchar_t Support

Built-in Codecs

Generic Codecs
UTF-8 Codecs
UTF-32 Codecs
UTF-16 Codecs
UTF-7 Codecs
Unicode-Escape Codecs
Raw-Unicode-Escape Codecs
Latin-1 Codecs
ASCII Codecs
Character Map Codecs
MBCS codecs for Windows
Methods & Slots

Container Objects

Dictionary Objects
Set Objects

Function Objects

Function Objects: Function Objects<3>.
Instance Method Objects
Method Objects: Method Objects<2>.
Cell Objects
Code Objects: Code Objects<2>.

Other Objects

File Objects
Module Objects
Iterator Objects
Descriptor Objects
Slice Objects
Ellipsis Object
MemoryView objects
Weak Reference Objects: Weak Reference Objects<2>.
Capsules: Capsules<2>.
Generator Objects
Coroutine Objects: Coroutine Objects<2>.
Context Variables Objects
DateTime Objects: DateTime Objects<2>.
Objects for Type Hinting

Module Objects

Initializing C modules
Module lookup

Initializing C modules

Single-phase initialization
Multi-phase initialization
Low-level module creation functions
Support functions

Initialization, Finalization, and Threads

Before Python Initialization
Global configuration variables
Initializing and finalizing the interpreter
Process-wide parameters
Thread State and the Global Interpreter Lock
Sub-interpreter support
Asynchronous Notifications
Profiling and Tracing
Advanced Debugger Support
Thread Local Storage Support

Thread State and the Global Interpreter Lock

Releasing the GIL from extension code
Non-Python created threads
Cautions about fork(): Cautions about fork.
High-level API
Low-level API

Sub-interpreter support

Bugs and caveats

Thread Local Storage Support

Thread Specific Storage (TSS) API: Thread Specific Storage TSS API.
Thread Local Storage (TLS) API: Thread Local Storage TLS API.

Thread Specific Storage (TSS) API

Dynamic Allocation
Methods: Methods<4>.

Python Initialization Configuration

Example: Example<18>.
PyWideStringList
PyStatus
PyPreConfig
Preinitialize Python with PyPreConfig
PyConfig
Initialization with PyConfig
Isolated Configuration
Python Configuration
Python Path Configuration
Py_RunMain(): Py_RunMain.
Py_GetArgcArgv(): Py_GetArgcArgv.
Multi-Phase Initialization Private Provisional API

Memory Management

Overview: Overview<4>.
Allocator Domains
Raw Memory Interface
Memory Interface
Object allocators
Default Memory Allocators
Customize Memory Allocators
Debug hooks on the Python memory allocators
The pymalloc allocator
tracemalloc C API
Examples: Examples<36>.

The pymalloc allocator

Customize pymalloc Arena Allocator

Object Implementation Support

Allocating Objects on the Heap
Common Object Structures
Type Objects: Type Objects<3>.
Number Object Structures
Mapping Object Structures
Sequence Object Structures
Buffer Object Structures
Async Object Structures
Slot Type typedefs
Examples: Examples<37>.
Supporting Cyclic Garbage Collection

Common Object Structures

Base object types and macros
Implementing functions and methods
Accessing attributes of extension types

Type Objects

Quick Reference
PyTypeObject Definition
PyObject Slots
PyVarObject Slots
PyTypeObject Slots
Static Types
Heap Types

Quick Reference

“tp slots”
sub-slots
slot typedefs

Supporting Cyclic Garbage Collection

Controlling the Garbage Collector State

Distributing Python Modules

Key terms
Open source licensing and collaboration
Installing the tools
Reading the Python Packaging User Guide
How do I…?

How do I…?

… choose a name for my project?
… create and distribute binary extensions?

Installing Python Modules

Key terms: Key terms<2>.
Basic usage
How do I …?
Common installation issues

How do I …?

… install pip in versions of Python prior to Python 3.4?: … install pip in versions of Python prior to Python 3 4?.
… install packages just for the current user?
… install scientific Python packages?
… work with multiple versions of Python installed in parallel?

Common installation issues

Installing into the system Python on Linux
Pip not installed
Installing binary extensions

Python HOWTOs

Porting Python 2 Code to Python 3
Porting Extension Modules to Python 3
Curses Programming with Python
Descriptor HowTo Guide
Functional Programming HOWTO
Logging HOWTO
Logging Cookbook
Regular Expression HOWTO
Socket Programming HOWTO
Sorting HOW TO
Unicode HOWTO
HOWTO Fetch Internet Resources Using The urllib Package
Argparse Tutorial
An introduction to the ipaddress module
Argument Clinic How-To
Instrumenting CPython with DTrace and SystemTap
Annotations Best Practices

Porting Python 2 Code to Python 3

The Short Explanation
Details

Details

Drop support for Python 2.6 and older: Drop support for Python 2 6 and older.
Make sure you specify the proper version support in your setup.py file: Make sure you specify the proper version support in your setup py file.
Have good test coverage
Learn the differences between Python 2 & 3
Update your code
Prevent compatibility regressions
Check which dependencies block your transition
Update your setup.py file to denote Python 3 compatibility: Update your setup py file to denote Python 3 compatibility.
Use continuous integration to stay compatible
Consider using optional static type checking

Update your code

Division
Text versus binary data
Use feature detection instead of version detection

Curses Programming with Python

What is curses?
Starting and ending a curses application
Windows and Pads
Displaying Text
User Input
For More Information

What is curses?

The Python curses module

Displaying Text

Attributes and Color

Descriptor HowTo Guide

Primer
Complete Practical Example
Technical Tutorial
Pure Python Equivalents

Primer

Simple example; A descriptor that returns a constant: Simple example A descriptor that returns a constant.
Dynamic lookups
Managed attributes
Customized names
Closing thoughts

Complete Practical Example

Validator class
Custom validators
Practical application

Technical Tutorial

Abstract
Definition and introduction
Descriptor protocol
Overview of descriptor invocation
Invocation from an instance
Invocation from a class
Invocation from super
Summary of invocation logic
Automatic name notification
ORM example

Pure Python Equivalents

Properties
Functions and methods
Kinds of methods
Static methods
Class methods
Member objects and __slots__

Functional Programming HOWTO

Introduction: Introduction<13>.
Iterators: Iterators<2>.
Generator expressions and list comprehensions
Generators: Generators<2>.
Built-in functions
The itertools module
The functools module
Small functions and the lambda expression
Revision History and Acknowledgements
References: References<2>.

Introduction

Formal provability
Modularity
Ease of debugging and testing
Composability

Iterators

Data Types That Support Iterators

Generators

Passing values into a generator

The itertools module

Creating new iterators
Calling functions on elements
Selecting elements
Combinatoric functions
Grouping elements

The functools module

The operator module

References

General
Python-specific
Python documentation

Logging HOWTO

Basic Logging Tutorial
Advanced Logging Tutorial
Logging Levels: Logging Levels<2>.
Useful Handlers
Exceptions raised during logging
Using arbitrary objects as messages
Optimization

Basic Logging Tutorial

When to use logging
A simple example
Logging to a file
Logging from multiple modules
Logging variable data
Changing the format of displayed messages
Displaying the date/time in messages
Next Steps

Advanced Logging Tutorial

Logging Flow
Loggers
Handlers
Formatters
Configuring Logging
What happens if no configuration is provided
Configuring Logging for a Library

Logging Levels

Custom Levels

Logging Cookbook

Using logging in multiple modules
Logging from multiple threads
Multiple handlers and formatters
Logging to multiple destinations
Custom handling of levels
Configuration server example
Dealing with handlers that block
Sending and receiving logging events across a network
Adding contextual information to your logging output
Use of contextvars
Imparting contextual information in handlers
Logging to a single file from multiple processes
Using file rotation
Use of alternative formatting styles
Customizing LogRecord
Subclassing QueueHandler - a ZeroMQ example
Subclassing QueueListener - a ZeroMQ example
An example dictionary-based configuration
Using a rotator and namer to customize log rotation processing
A more elaborate multiprocessing example
Inserting a BOM into messages sent to a SysLogHandler
Implementing structured logging
Customizing handlers with dictConfig(): Customizing handlers with dictConfig.
Using particular formatting styles throughout your application
Configuring filters with dictConfig(): Configuring filters with dictConfig.
Customized exception formatting
Speaking logging messages
Buffering logging messages and outputting them conditionally
Sending logging messages to email, with buffering: Sending logging messages to email with buffering.
Formatting times using UTC (GMT) via configuration: Formatting times using UTC GMT via configuration.
Using a context manager for selective logging
A CLI application starter template
A Qt GUI for logging
Logging to syslog with RFC5424 support
How to treat a logger like an output stream
Patterns to avoid
Other resources

Sending and receiving logging events across a network

Running a logging socket listener in production

Adding contextual information to your logging output

Using LoggerAdapters to impart contextual information
Using Filters to impart contextual information

Using LoggerAdapters to impart contextual information

Using objects other than dicts to pass contextual information

Logging to a single file from multiple processes

Using concurrent.futures.ProcessPoolExecutor: Using concurrent futures ProcessPoolExecutor.
Deploying Web applications using Gunicorn and uWSGI

Using particular formatting styles throughout your application

Using LogRecord factories
Using custom message objects

Patterns to avoid

Opening the same log file multiple times
Using loggers as attributes in a class or passing them as parameters
Adding handlers other than NullHandler to a logger in a library
Creating a lot of loggers

Regular Expression HOWTO

Introduction: Introduction<14>.
Simple Patterns
Using Regular Expressions
More Pattern Power
Modifying Strings
Common Problems
Feedback

Simple Patterns

Matching Characters
Repeating Things

Using Regular Expressions

Compiling Regular Expressions
The Backslash Plague
Performing Matches
Module-Level Functions: Module-Level Functions<2>.
Compilation Flags

More Pattern Power

More Metacharacters
Grouping
Non-capturing and Named Groups
Lookahead Assertions

Modifying Strings

Splitting Strings
Search and Replace: Search and Replace<2>.

Common Problems

Use String Methods
match() versus search(): match versus search.
Greedy versus Non-Greedy
Using re.VERBOSE: Using re VERBOSE.

Socket Programming HOWTO

Sockets
Creating a Socket
Using a Socket
Disconnecting
Non-blocking Sockets

Sockets

History

Creating a Socket

IPC

Using a Socket

Binary Data

Disconnecting

When Sockets Die

Sorting HOW TO

Sorting Basics
Key Functions
Operator Module Functions
Ascending and Descending
Sort Stability and Complex Sorts
The Old Way Using Decorate-Sort-Undecorate
The Old Way Using the cmp Parameter
Odd and Ends

Unicode HOWTO

Introduction to Unicode
Python’s Unicode Support
Reading and Writing Unicode Data
Acknowledgements: Acknowledgements<10>.

Introduction to Unicode

Definitions
Encodings
References: References<3>.

Python’s Unicode Support

The String Type
Converting to Bytes
Unicode Literals in Python Source Code
Unicode Properties
Comparing Strings
Unicode Regular Expressions
References: References<4>.

Reading and Writing Unicode Data

Unicode filenames
Tips for Writing Unicode-aware Programs
References: References<5>.

Tips for Writing Unicode-aware Programs

Converting Between File Encodings
Files in an Unknown Encoding

HOWTO Fetch Internet Resources Using The urllib Package

Introduction: Introduction<15>.
Fetching URLs
Handling Exceptions: Handling Exceptions<2>.
info and geturl
Openers and Handlers
Basic Authentication
Proxies
Sockets and Layers
Footnotes

Fetching URLs

Data
Headers

Handling Exceptions

URLError
HTTPError
Wrapping it Up

HTTPError

Error Codes

Wrapping it Up

Number 1
Number 2

Argparse Tutorial

Concepts
The basics
Introducing Positional arguments
Introducing Optional arguments
Combining Positional and Optional arguments
Getting a little more advanced
Conclusion

Introducing Optional arguments

Short options

Getting a little more advanced

Conflicting options

An introduction to the ipaddress module

Creating Address/Network/Interface objects
Inspecting Address/Network/Interface Objects
Networks as lists of Addresses
Comparisons: Comparisons<4>.
Using IP Addresses with other modules
Getting more detail when instance creation fails

Creating Address/Network/Interface objects

A Note on IP Versions
IP Host Addresses
Defining Networks
Host Interfaces

Argument Clinic How-To

The Goals Of Argument Clinic
Basic Concepts And Usage
Converting Your First Function
Advanced Topics

Advanced Topics

Symbolic default values
Renaming the C functions and variables generated by Argument Clinic
Converting functions using PyArg_UnpackTuple
Optional Groups
Using real Argument Clinic converters, instead of “legacy converters”: Using real Argument Clinic converters instead of “legacy converters”.
Py_buffer
Advanced converters
Parameter default values
The NULL default value
Expressions specified as default values
Using a return converter
Cloning existing functions
Calling Python code
Using a “self converter”
Using a “defining class” converter
Writing a custom converter
Writing a custom return converter
METH_O and METH_NOARGS
tp_new and tp_init functions
Changing and redirecting Clinic’s output
The #ifdef trick
Using Argument Clinic in Python files

Instrumenting CPython with DTrace and SystemTap

Enabling the static markers
Static DTrace probes
Static SystemTap markers
Available static markers
SystemTap Tapsets
Examples: Examples<38>.

Annotations Best Practices

Accessing The Annotations Dict Of An Object In Python 3.10 And Newer: Accessing The Annotations Dict Of An Object In Python 3 10 And Newer.
Accessing The Annotations Dict Of An Object In Python 3.9 And Older: Accessing The Annotations Dict Of An Object In Python 3 9 And Older.
Manually Un-Stringizing Stringized Annotations
Best Practices For __annotations__ In Any Python Version
__annotations__ Quirks

Python Frequently Asked Questions

General Python FAQ
Programming FAQ
Design and History FAQ
Library and Extension FAQ
Extending/Embedding FAQ
Python on Windows FAQ
Graphic User Interface FAQ
“Why is Python Installed on my Computer?” FAQ

General Python FAQ

General Information
Python in the real world

General Information

What is Python?
What is the Python Software Foundation?
Are there copyright restrictions on the use of Python?
Why was Python created in the first place?
What is Python good for?
How does the Python version numbering scheme work?
How do I obtain a copy of the Python source?
How do I get documentation on Python?
I’ve never programmed before. Is there a Python tutorial?: I’ve never programmed before Is there a Python tutorial?.
Is there a newsgroup or mailing list devoted to Python?
How do I get a beta test version of Python?
How do I submit bug reports and patches for Python?
Are there any published articles about Python that I can reference?
Are there any books on Python?
Where in the world is www.python.org located?: Where in the world is www python org located?.
Why is it called Python?
Do I have to like “Monty Python’s Flying Circus”?

Python in the real world

How stable is Python?
How many people are using Python?
Have any significant projects been done in Python?
What new developments are expected for Python in the future?
Is it reasonable to propose incompatible changes to Python?
Is Python a good language for beginning programmers?

Programming FAQ

General Questions
Core Language
Numbers and strings
Performance: Performance<4>.
Sequences (Tuples/Lists): Sequences Tuples/Lists.
Objects
Modules: Modules<3>.

General Questions

Is there a source code level debugger with breakpoints, single-stepping, etc.?: Is there a source code level debugger with breakpoints single-stepping etc ?.
Are there tools to help find bugs or perform static analysis?
How can I create a stand-alone binary from a Python script?
Are there coding standards or a style guide for Python programs?

Core Language

Why am I getting an UnboundLocalError when the variable has a value?
What are the rules for local and global variables in Python?
Why do lambdas defined in a loop with different values all return the same result?
How do I share global variables across modules?
What are the “best practices” for using import in a module?
Why are default values shared between objects?
How can I pass optional or keyword parameters from one function to another?
What is the difference between arguments and parameters?
Why did changing list ‘y’ also change list ‘x’?
How do I write a function with output parameters (call by reference)?: How do I write a function with output parameters call by reference ?.
How do you make a higher order function in Python?
How do I copy an object in Python?
How can I find the methods or attributes of an object?
How can my code discover the name of an object?
What’s up with the comma operator’s precedence?
Is there an equivalent of C’s “?;” ternary operator?: Is there an equivalent of C’s “? ” ternary operator?.
Is it possible to write obfuscated one-liners in Python?
What does the slash(/) in the parameter list of a function mean?: What does the slash / in the parameter list of a function mean?.

Numbers and strings

How do I specify hexadecimal and octal integers?
Why does -22 // 10 return -3?
How do I get int literal attribute instead of SyntaxError?
How do I convert a string to a number?
How do I convert a number to a string?
How do I modify a string in place?
How do I use strings to call functions/methods?
Is there an equivalent to Perl’s chomp() for removing trailing newlines from strings?: Is there an equivalent to Perl’s chomp for removing trailing newlines from strings?.
Is there a scanf() or sscanf() equivalent?: Is there a scanf or sscanf equivalent?.
What does ‘UnicodeDecodeError’ or ‘UnicodeEncodeError’ error mean?
Can I end a raw string with an odd number of backslashes?

Performance

My program is too slow. How do I speed it up?: My program is too slow How do I speed it up?.
What is the most efficient way to concatenate many strings together?

Sequences (Tuples/Lists)

How do I convert between tuples and lists?
What’s a negative index?
How do I iterate over a sequence in reverse order?
How do you remove duplicates from a list?
How do you remove multiple items from a list
How do you make an array in Python?
How do I create a multidimensional list?
How do I apply a method to a sequence of objects?
Why does a_tuple[i] += [‘item’] raise an exception when the addition works?
I want to do a complicated sort; can you do a Schwartzian Transform in Python?: I want to do a complicated sort can you do a Schwartzian Transform in Python?.
How can I sort one list by values from another list?

Objects

What is a class?
What is a method?
What is self?
How do I check if an object is an instance of a given class or of a subclass of it?
What is delegation?
How do I call a method defined in a base class from a derived class that extends it?
How can I organize my code to make it easier to change the base class?
How do I create static class data and static class methods?
How can I overload constructors (or methods) in Python?: How can I overload constructors or methods in Python?.
I try to use __spam and I get an error about _SomeClassName__spam.: I try to use __spam and I get an error about _SomeClassName__spam.
My class defines __del__ but it is not called when I delete the object.: My class defines __del__ but it is not called when I delete the object.
How do I get a list of all instances of a given class?
Why does the result of id() appear to be not unique?: Why does the result of id appear to be not unique?.
When can I rely on identity tests with the is operator?
How can a subclass control what data is stored in an immutable instance?
How do I cache method calls?

Modules

How do I create a .pyc file?: How do I create a pyc file?.
How do I find the current module name?
How can I have modules that mutually import each other?
__import__(‘x.y.z’) returns <module ‘x’>; how do I get z?: __import__ ‘x y z’ returns <module ‘x’>; how do I get z?.
When I edit an imported module and reimport it, the changes don’t show up. Why does this happen?: When I edit an imported module and reimport it the changes don’t show up Why does this happen?.

Design and History FAQ

Why does Python use indentation for grouping of statements?
Why am I getting strange results with simple arithmetic operations?
Why are floating-point calculations so inaccurate?
Why are Python strings immutable?
Why must ‘self’ be used explicitly in method definitions and calls?
Why can’t I use an assignment in an expression?
Why does Python use methods for some functionality (e.g. list.index()) but functions for other (e.g. len(list))?: Why does Python use methods for some functionality e g list index but functions for other e g len list ?.
Why is join() a string method instead of a list or tuple method?: Why is join a string method instead of a list or tuple method?.
How fast are exceptions?
Why isn’t there a switch or case statement in Python?
Can’t you emulate threads in the interpreter instead of relying on an OS-specific thread implementation?
Why can’t lambda expressions contain statements?
Can Python be compiled to machine code, C or some other language?: Can Python be compiled to machine code C or some other language?.
How does Python manage memory?
Why doesn’t CPython use a more traditional garbage collection scheme?
Why isn’t all memory freed when CPython exits?
Why are there separate tuple and list data types?
How are lists implemented in CPython?
How are dictionaries implemented in CPython?
Why must dictionary keys be immutable?
Why doesn’t list.sort() return the sorted list?: Why doesn’t list sort return the sorted list?.
How do you specify and enforce an interface spec in Python?
Why is there no goto?
Why can’t raw strings (r-strings) end with a backslash?: Why can’t raw strings r-strings end with a backslash?.
Why doesn’t Python have a “with” statement for attribute assignments?
Why don’t generators support the with statement?
Why are colons required for the if/while/def/class statements?
Why does Python allow commas at the end of lists and tuples?

Library and Extension FAQ

General Library Questions
Common tasks
Threads
Input and Output: Input and Output<2>.
Network/Internet Programming
Databases
Mathematics and Numerics

General Library Questions

How do I find a module or application to perform task X?
Where is the math.py (socket.py, regex.py, etc.) source file?: Where is the math py socket py regex py etc source file?.
How do I make a Python script executable on Unix?
Is there a curses/termcap package for Python?
Is there an equivalent to C’s onexit() in Python?: Is there an equivalent to C’s onexit in Python?.
Why don’t my signal handlers work?

Common tasks

How do I test a Python program or component?
How do I create documentation from doc strings?
How do I get a single keypress at a time?

Threads

How do I program using threads?
None of my threads seem to run; why?: None of my threads seem to run why?.
How do I parcel out work among a bunch of worker threads?
What kinds of global value mutation are thread-safe?
Can’t we get rid of the Global Interpreter Lock?

Input and Output

How do I delete a file? (And other file questions…): How do I delete a file? And other file questions….
How do I copy a file?
How do I read (or write) binary data?: How do I read or write binary data?.
I can’t seem to use os.read() on a pipe created with os.popen(); why?: I can’t seem to use os read on a pipe created with os popen ; why?.
How do I access the serial (RS232) port?: How do I access the serial RS232 port?.
Why doesn’t closing sys.stdout (stdin, stderr) really close it?: Why doesn’t closing sys stdout stdin stderr really close it?.

Network/Internet Programming

What WWW tools are there for Python?
How can I mimic CGI form submission (METHOD=POST)?: How can I mimic CGI form submission METHOD=POST ?.
What module should I use to help with generating HTML?
How do I send mail from a Python script?
How do I avoid blocking in the connect() method of a socket?: How do I avoid blocking in the connect method of a socket?.

Databases

Are there any interfaces to database packages in Python?
How do you implement persistent objects in Python?

Mathematics and Numerics

How do I generate random numbers in Python?

Extending/Embedding FAQ

Can I create my own functions in C?
Can I create my own functions in C++?
Writing C is hard; are there any alternatives?
How can I execute arbitrary Python statements from C?
How can I evaluate an arbitrary Python expression from C?
How do I extract C values from a Python object?
How do I use Py_BuildValue() to create a tuple of arbitrary length?: How do I use Py_BuildValue to create a tuple of arbitrary length?.
How do I call an object’s method from C?
How do I catch the output from PyErr_Print() (or anything that prints to stdout/stderr)?: How do I catch the output from PyErr_Print or anything that prints to stdout/stderr ?.
How do I access a module written in Python from C?
How do I interface to C++ objects from Python?
I added a module using the Setup file and the make fails; why?
How do I debug an extension?
I want to compile a Python module on my Linux system, but some files are missing. Why?: I want to compile a Python module on my Linux system but some files are missing Why?.
How do I tell “incomplete input” from “invalid input”?
How do I find undefined g++ symbols __builtin_new or __pure_virtual?
Can I create an object class with some methods implemented in C and others in Python (e.g. through inheritance)?: Can I create an object class with some methods implemented in C and others in Python e g through inheritance ?.

Python on Windows FAQ

How do I run a Python program under Windows?
How do I make Python scripts executable?
Why does Python sometimes take so long to start?
How do I make an executable from a Python script?
Is a *.pyd file the same as a DLL?: Is a * pyd file the same as a DLL?.
How can I embed Python into a Windows application?
How do I keep editors from inserting tabs into my Python source?
How do I check for a keypress without blocking?
How do I solve the missing api-ms-win-crt-runtime-l1-1-0.dll error?: How do I solve the missing api-ms-win-crt-runtime-l1-1-0 dll error?.

Graphic User Interface FAQ

General GUI Questions
What GUI toolkits exist for Python?
Tkinter questions

Tkinter questions

How do I freeze Tkinter applications?
Can I have Tk events handled while waiting for I/O?
I can’t get key bindings to work in Tkinter; why?: I can’t get key bindings to work in Tkinter why?.

“Why is Python Installed on my Computer?” FAQ

What is Python?: What is Python?<2>.
Why is Python installed on my machine?
Can I delete Python?

About these documents

Contributors to the Python Documentation

Dealing with Bugs

Documentation bugs
Using the Python issue tracker
Getting started contributing to Python yourself

History and License

History of the software
Terms and conditions for accessing or otherwise using Python
Licenses and Acknowledgements for Incorporated Software

Terms and conditions for accessing or otherwise using Python

PSF LICENSE AGREEMENT FOR PYTHON 3.10.12: PSF LICENSE AGREEMENT FOR PYTHON 3 10 12.
BEOPEN.COM LICENSE AGREEMENT FOR PYTHON 2.0: BEOPEN COM LICENSE AGREEMENT FOR PYTHON 2 0.
CNRI LICENSE AGREEMENT FOR PYTHON 1.6.1: CNRI LICENSE AGREEMENT FOR PYTHON 1 6 1.
CWI LICENSE AGREEMENT FOR PYTHON 0.9.0 THROUGH 1.2: CWI LICENSE AGREEMENT FOR PYTHON 0 9 0 THROUGH 1 2.
ZERO-CLAUSE BSD LICENSE FOR CODE IN THE PYTHON 3.10.12 DOCUMENTATION: ZERO-CLAUSE BSD LICENSE FOR CODE IN THE PYTHON 3 10 12 DOCUMENTATION.

Licenses and Acknowledgements for Incorporated Software

Mersenne Twister
Sockets: Sockets<2>.
Asynchronous socket services
Cookie management
Execution tracing
UUencode and UUdecode functions
XML Remote Procedure Calls
test_epoll
Select kqueue
SipHash24
strtod and dtoa
OpenSSL
expat
libffi
zlib: zlib<3>.
cfuhash
libmpdec
W3C C14N test suite
Audioop

Distributing Python Modules (Legacy version)

An Introduction to Distutils
Writing the Setup Script
Writing the Setup Configuration File
Creating a Source Distribution
Creating Built Distributions
Distutils Examples
Extending Distutils
Command Reference
API Reference

An Introduction to Distutils

Concepts & Terminology
A Simple Example: A Simple Example<2>.
General Python terminology
Distutils-specific terminology

Writing the Setup Script

Listing whole packages
Listing individual modules
Describing extension modules
Relationships between Distributions and Packages
Installing Scripts
Installing Package Data
Installing Additional Files
Additional meta-data
Debugging the setup script

Describing extension modules

Extension names and packages
Extension source files
Preprocessor options
Library options
Other options

Creating a Source Distribution

Specifying the files to distribute
Manifest-related options

Creating Built Distributions

Creating RPM packages
Cross-compiling on Windows

Cross-compiling on Windows

The Postinstallation script

Distutils Examples

Pure Python distribution (by module): Pure Python distribution by module.
Pure Python distribution (by package): Pure Python distribution by package.
Single extension module
Checking a package
Reading the metadata

Extending Distutils

Integrating new commands
Adding new distribution types

Command Reference

Installing modules; the install command family: Installing modules the install command family.
Creating a source distribution; the sdist command: Creating a source distribution the sdist command.

Installing modules: the install command family

install_data
install_scripts

API Reference

distutils.core — Core Distutils functionality: distutils core — Core Distutils functionality.
distutils.ccompiler — CCompiler base class: distutils ccompiler — CCompiler base class.
distutils.unixccompiler — Unix C Compiler: distutils unixccompiler — Unix C Compiler.
distutils.msvccompiler — Microsoft Compiler: distutils msvccompiler — Microsoft Compiler.
distutils.bcppcompiler — Borland Compiler: distutils bcppcompiler — Borland Compiler.
distutils.cygwincompiler — Cygwin Compiler: distutils cygwincompiler — Cygwin Compiler.
distutils.archive_util — Archiving utilities: distutils archive_util — Archiving utilities.
distutils.dep_util — Dependency checking: distutils dep_util — Dependency checking.
distutils.dir_util — Directory tree operations: distutils dir_util — Directory tree operations.
distutils.file_util — Single file operations: distutils file_util — Single file operations.
distutils.util — Miscellaneous other utility functions: distutils util — Miscellaneous other utility functions.
distutils.dist — The Distribution class: distutils dist — The Distribution class.
distutils.extension — The Extension class: distutils extension — The Extension class.
distutils.debug — Distutils debug mode: distutils debug — Distutils debug mode.
distutils.errors — Distutils exceptions: distutils errors — Distutils exceptions.
distutils.fancy_getopt — Wrapper around the standard getopt module: distutils fancy_getopt — Wrapper around the standard getopt module.
distutils.filelist — The FileList class: distutils filelist — The FileList class.
distutils.log — Simple PEP 282-style logging: distutils log — Simple PEP 282-style logging.
distutils.spawn — Spawn a sub-process: distutils spawn — Spawn a sub-process.
distutils.sysconfig — System configuration information: distutils sysconfig — System configuration information.
distutils.text_file — The TextFile class: distutils text_file — The TextFile class.
distutils.version — Version number classes: distutils version — Version number classes.
distutils.cmd — Abstract base class for Distutils commands: distutils cmd — Abstract base class for Distutils commands.
Creating a new Distutils command
distutils.command — Individual Distutils commands: distutils command — Individual Distutils commands.
distutils.command.bdist — Build a binary installer: distutils command bdist — Build a binary installer.
distutils.command.bdist_packager — Abstract base class for packagers: distutils command bdist_packager — Abstract base class for packagers.
distutils.command.bdist_dumb — Build a “dumb” installer: distutils command bdist_dumb — Build a “dumb” installer.
distutils.command.bdist_msi — Build a Microsoft Installer binary package: distutils command bdist_msi — Build a Microsoft Installer binary package.
distutils.command.bdist_rpm — Build a binary distribution as a Redhat RPM and SRPM: distutils command bdist_rpm — Build a binary distribution as a Redhat RPM and SRPM.
distutils.command.sdist — Build a source distribution: distutils command sdist — Build a source distribution.
distutils.command.build — Build all files of a package: distutils command build — Build all files of a package.
distutils.command.build_clib — Build any C libraries in a package: distutils command build_clib — Build any C libraries in a package.
distutils.command.build_ext — Build any extensions in a package: distutils command build_ext — Build any extensions in a package.
distutils.command.build_py — Build the .py/.pyc files of a package: distutils command build_py — Build the py/ pyc files of a package.
distutils.command.build_scripts — Build the scripts of a package: distutils command build_scripts — Build the scripts of a package.
distutils.command.clean — Clean a package build area: distutils command clean — Clean a package build area.
distutils.command.config — Perform package configuration: distutils command config — Perform package configuration.
distutils.command.install — Install a package: distutils command install — Install a package.
distutils.command.install_data — Install data files from a package: distutils command install_data — Install data files from a package.
distutils.command.install_headers — Install C/C++ header files from a package: distutils command install_headers — Install C/C++ header files from a package.
distutils.command.install_lib — Install library files from a package: distutils command install_lib — Install library files from a package.
distutils.command.install_scripts — Install script files from a package: distutils command install_scripts — Install script files from a package.
distutils.command.register — Register a module with the Python Package Index: distutils command register — Register a module with the Python Package Index.
distutils.command.check — Check the meta-data of a package: distutils command check — Check the meta-data of a package.

Installing Python Modules (Legacy version)

Introduction: Introduction<16>.
Standard Build and Install
Alternate Installation
Custom Installation
Distutils Configuration Files
Building Extensions; Tips and Tricks: Building Extensions Tips and Tricks.

Introduction

Distutils based source distributions

Standard Build and Install

Platform variations
Splitting the job up
How building works
How installation works

Alternate Installation

Alternate installation; the user scheme: Alternate installation the user scheme.
Alternate installation; the home scheme: Alternate installation the home scheme.
Alternate installation; Unix (the prefix scheme): Alternate installation Unix the prefix scheme.
Alternate installation; Windows (the prefix scheme): Alternate installation Windows the prefix scheme.

Custom Installation

Modifying Python’s Search Path

Distutils Configuration Files

Location and names of config files
Syntax of config files

Building Extensions: Tips and Tricks

Tweaking compiler/linker flags
Using non-Microsoft compilers on Windows

Using non-Microsoft compilers on Windows

Borland/CodeGear C++
GNU C / Cygwin / MinGW

GNU C / Cygwin / MinGW

Older Versions of Python and MinGW