Python 3.7.3 documentation
Table of contents
- 3.7.3 Documentation
- Python Module Index
-
Whats New in Python
-
Whats New In Python 3.7
- Summary Release Highlights
-
New Features
- PEP 563: Postponed Evaluation of Annotations
- PEP 538: Legacy C Locale Coercion
- PEP 540: Forced UTF-8 Runtime Mode
- PEP 553: Built-in breakpoint()
- PEP 539: New C API for Thread-Local Storage
- PEP 562: Customization of Access to Module Attributes
- PEP 564: New Time Functions With Nanosecond Resolution
- PEP 565: Show DeprecationWarning in __main__
- PEP 560: Core Support for typing module and Generic Types
- PEP 552: Hash-based .pyc Files
- PEP 545: Python Documentation Translations
- Development Runtime Mode: -X dev
- Other Language Changes
- New Modules
-
Improved Modules
- argparse
- asyncio
- binascii
- calendar
- collections
- compileall
- concurrent.futures
- contextlib
- cProfile
- crypt
- datetime
- dbm
- decimal
- dis
- distutils
- enum
- functools
- gc
- hmac
- http.client
- http.server
- idlelib and IDLE
- importlib
- io
- ipaddress
- itertools
- locale
- logging
- math
- mimetypes
- msilib
- multiprocessing
- os
- pathlib
- pdb
- py_compile
- pydoc
- queue
- re
- signal
- socket
- socketserver
- sqlite3
- ssl
- string
- subprocess
- sys
- time
- tkinter
- tracemalloc
- types
- unicodedata
- unittest
- unittest.mock
- urllib.parse
- uu
- uuid
- warnings
- xml
- xml.etree
- xmlrpc.server
- zipapp
- zipfile
- C API Changes
- Build Changes
- Optimizations
- Other CPython Implementation Changes
- Deprecated Python Behavior
- Deprecated Python modules, functions and methods
- Deprecated functions and types of the C API
- Platform Support Removals
- API and Feature Removals
- Module Removals
- Windows-only Changes
- Porting to Python 3.7
- Notable changes in Python 3.7.1
- Notable changes in Python 3.7.2
-
Whats New In Python 3.6
- Summary Release highlights
-
New Features
- PEP 498: Formatted string literals
- PEP 526: Syntax for variable annotations
- PEP 515: Underscores in Numeric Literals
- PEP 525: Asynchronous Generators
- PEP 530: Asynchronous Comprehensions
- PEP 487: Simpler customization of class creation
- PEP 487: Descriptor Protocol Enhancements
- PEP 519: Adding a file system path protocol
- PEP 495: Local Time Disambiguation
- PEP 529: Change Windows filesystem encoding to UTF-8
- PEP 528: Change Windows console encoding to UTF-8
- PEP 520: Preserving Class Attribute Definition Order
- PEP 468: Preserving Keyword Argument Order
- New dict implementation
- PEP 523: Adding a frame evaluation API to CPython
- PYTHONMALLOC environment variable
- DTrace and SystemTap probing support
- Other Language Changes
- New Modules
-
Improved Modules
- array
- ast
- asyncio
- binascii
- cmath
- collections
- concurrent.futures
- contextlib
- datetime
- decimal
- distutils
- encodings
- enum
- faulthandler
- fileinput
- hashlib
- http.client
- idlelib and IDLE
- importlib
- inspect
- json
- logging
- math
- multiprocessing
- os
- pathlib
- pdb
- pickle
- pickletools
- pydoc
- random
- re
- readline
- rlcompleter
- shlex
- site
- sqlite3
- socket
- socketserver
- ssl
- statistics
- struct
- subprocess
- sys
- telnetlib
- time
- timeit
- tkinter
- traceback
- tracemalloc
- typing
- unicodedata
- unittest.mock
- urllib.request
- urllib.robotparser
- venv
- warnings
- winreg
- winsound
- xmlrpc.client
- zipfile
- zlib
- Optimizations
- Build and C API Changes
- Other Improvements
- Deprecated
- Removed
- Porting to Python 3.6
- Notable changes in Python 3.6.2
- Notable changes in Python 3.6.4
- Notable changes in Python 3.6.5
- Notable changes in Python 3.6.7
-
Whats New In Python 3.5
- Summary Release highlights
-
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 475: Retry system calls failing with EINTR
- PEP 479: Change StopIteration handling inside generators
- PEP 485: A function for testing approximate equality
- PEP 486: Make the Python Launcher aware of virtual environments
- PEP 488: Elimination of PYO files
- PEP 489: Multi-phase extension module initialization
- Other Language Changes
- New Modules
-
Improved Modules
- argparse
- asyncio
- bz2
- cgi
- cmath
- code
- collections
- collections.abc
- compileall
- concurrent.futures
- configparser
- contextlib
- csv
- curses
- dbm
- difflib
- distutils
- doctest
- enum
- faulthandler
- functools
- glob
- gzip
- heapq
- http
- http.client
- idlelib and IDLE
- imaplib
- imghdr
- importlib
- inspect
- io
- ipaddress
- json
- linecache
- locale
- logging
- lzma
- math
- multiprocessing
- operator
- os
- pathlib
- pickle
- poplib
- re
- readline
- selectors
- shutil
- signal
- smtpd
- smtplib
- sndhdr
- socket
- ssl
- sqlite3
- subprocess
- sys
- sysconfig
- tarfile
- threading
- time
- timeit
- tkinter
- traceback
- types
- unicodedata
- unittest
- unittest.mock
- urllib
- wsgiref
- xmlrpc
- xml.sax
- zipfile
- Other module-level changes
- Optimizations
- Build and C API Changes
- Deprecated
- Removed
- Porting to Python 3.5
- Notable changes in Python 3.5.4
-
Whats New In Python 3.4
- Summary Release Highlights
- New Features
- New Modules
-
Improved Modules
- abc
- aifc
- argparse
- audioop
- base64
- collections
- colorsys
- contextlib
- dbm
- dis
- doctest
- filecmp
- functools
- gc
- glob
- hashlib
- hmac
- html
- http
- idlelib and IDLE
- importlib
- inspect
- ipaddress
- logging
- marshal
- mmap
- multiprocessing
- operator
- os
- pdb
- pickle
- plistlib
- poplib
- pprint
- pty
- pydoc
- re
- resource
- select
- shelve
- shutil
- smtpd
- smtplib
- socket
- sqlite3
- ssl
- stat
- struct
- subprocess
- sunau
- sys
- tarfile
- textwrap
- threading
- traceback
- types
- urllib
- unittest
- venv
- wave
- weakref
- xml.etree
- zipfile
- CPython Implementation Changes
- Deprecated
- Removed
- Porting to Python 3.4
- Changed in 3.4.3
-
Whats New In Python 3.3
- Summary Release highlights
- PEP 405: Virtual Environments
- PEP 420: Implicit Namespace Packages
- PEP 3118: New memoryview implementation and buffer protocol documentation
- PEP 393: Flexible String Representation
- PEP 397: Python Launcher for Windows
- PEP 3151: Reworking the OS and IO exception hierarchy
- PEP 380: Syntax for Delegating to a Subgenerator
- PEP 409: Suppressing exception context
- PEP 414: Explicit Unicode literals
- PEP 3155: Qualified name for classes and functions
- PEP 412: Key-Sharing Dictionary
- PEP 362: Function Signature Object
- PEP 421: Adding sys.implementation
- Using importlib as the Implementation of Import
- Other Language Changes
- A Finer-Grained Import Lock
- Builtin functions and types
- New Modules
-
Improved Modules
- abc
- array
- base64
- binascii
- bz2
- codecs
- collections
- contextlib
- crypt
- curses
- datetime
- decimal
- ftplib
- functools
- gc
- hmac
- http
- html
- imaplib
- inspect
- io
- itertools
- logging
- math
- mmap
- multiprocessing
- nntplib
- os
- pdb
- pickle
- pydoc
- re
- sched
- select
- shlex
- shutil
- signal
- smtpd
- smtplib
- socket
- socketserver
- sqlite3
- ssl
- stat
- struct
- subprocess
- sys
- tarfile
- tempfile
- textwrap
- threading
- time
- types
- unittest
- urllib
- webbrowser
- xml.etree.ElementTree
- zlib
- Optimizations
- Build and C API Changes
- Deprecated
- Porting to Python 3.3
-
Whats New In Python 3.2
- PEP 384: Defining a Stable ABI
- PEP 389: Argparse Command Line Parsing Module
- PEP 391: Dictionary Based Configuration for Logging
- PEP 3148: The concurrent.futures module
- PEP 3147: PYC Repository Directories
- PEP 3149: ABI Version Tagged .so Files
- PEP 3333: Python Web Server Gateway Interface v1.0.1
- Other Language Changes
-
New, Improved, and Deprecated Modules
- elementtree
- functools
- itertools
- collections
- threading
- datetime and time
- math
- abc
- io
- reprlib
- logging
- csv
- contextlib
- decimal and fractions
- ftp
- popen
- select
- gzip and zipfile
- tarfile
- hashlib
- ast
- os
- shutil
- sqlite3
- html
- socket
- ssl
- nntp
- certificates
- imaplib
- http.client
- unittest
- random
- poplib
- asyncore
- tempfile
- inspect
- pydoc
- dis
- dbm
- ctypes
- site
- sysconfig
- pdb
- configparser
- urllib.parse
- mailbox
- turtledemo
- Multi-threading
- Optimizations
- Unicode
- Codecs
- Documentation
- IDLE
- Code Repository
- Build and C API Changes
- Porting to Python 3.2
- Whats New In Python 3.1
- Whats New In Python 3.0
-
Whats New in Python 2.7
- The Future for Python 2.x
- Changes to the Handling of Deprecation Warnings
- Python 3.1 Features
- PEP 372: Adding an Ordered Dictionary to collections
- PEP 378: Format Specifier for Thousands Separator
- PEP 389: The argparse Module for Parsing Command Lines
- PEP 391: Dictionary-Based Configuration For Logging
- PEP 3106: Dictionary Views
- PEP 3137: The memoryview Object
- Other Language Changes
- New and Improved Modules
- Build and C API Changes
- Other Changes and Fixes
- Porting to Python 2.7
-
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 466: Network Security Enhancements for 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 493: HTTPS verification migration tools for Python 2.7
- New make regen-all build target
- Removal of make touch build target
- Acknowledgements
-
Whats New in Python 2.6
- Python 3.0
- Changes to the Development Process
- PEP 343: The with statement
- PEP 366: Explicit Relative Imports From a Main Module
- PEP 370: Per-user site-packages Directory
- PEP 371: The multiprocessing Package
- PEP 3101: Advanced String Formatting
- PEP 3105: print As a Function
- PEP 3110: Exception-Handling Changes
- PEP 3112: Byte Literals
- PEP 3116: New I/O Library
- PEP 3118: Revised Buffer Protocol
- PEP 3119: Abstract Base Classes
- PEP 3127: Integer Literal Support and Syntax
- PEP 3129: Class Decorators
- PEP 3141: A Type Hierarchy for Numbers
- Other Language Changes
- New and Improved Modules
- Deprecations and Removals
- Build and C API Changes
- Porting to Python 2.6
- Acknowledgements
-
Whats New in Python 2.5
- PEP 308: Conditional Expressions
- PEP 309: Partial Function Application
- PEP 314: Metadata for Python Software Packages v1.1
- PEP 328: Absolute and Relative Imports
- PEP 338: Executing Modules as Scripts
- PEP 341: Unified try/except/finally
- PEP 342: New Generator Features
- PEP 343: The with statement
- PEP 352: Exceptions as New-Style Classes
- PEP 353: Using ssize_t as the index type
- PEP 357: The __index__ method
- Other Language Changes
- New, Improved, and Removed Modules
- Build and C API Changes
- Porting to Python 2.5
- Acknowledgements
-
Whats New in Python 2.4
- PEP 218: Built-In Set Objects
- PEP 237: Unifying Long Integers and Integers
- PEP 289: Generator Expressions
- PEP 292: Simpler String Substitutions
- PEP 318: Decorators for Functions and Methods
- PEP 322: Reverse Iteration
- PEP 324: New subprocess Module
- PEP 327: Decimal Data Type
- PEP 328: Multi-line Imports
- PEP 331: Locale-Independent Float/String Conversions
- Other Language Changes
- New, Improved, and Deprecated Modules
- Build and C API Changes
- Porting to Python 2.4
- Acknowledgements
-
Whats New in Python 2.3
- PEP 218: A Standard Set Datatype
- PEP 255: Simple Generators
- PEP 263: Source Code Encodings
- PEP 273: Importing Modules from ZIP Archives
- PEP 277: Unicode file name support for Windows NT
- PEP 278: Universal Newline Support
- PEP 279: enumerate()
- PEP 282: The logging Package
- PEP 285: A Boolean Type
- PEP 293: Codec Error Handling Callbacks
- PEP 301: Package Index and Metadata for Distutils
- PEP 302: New Import Hooks
- PEP 305: Comma-separated Files
- PEP 307: Pickle Enhancements
- Extended Slices
- Other Language Changes
- New, Improved, and Deprecated Modules
- Pymalloc: A Specialized Object Allocator
- Build and C API Changes
- Other Changes and Fixes
- Porting to Python 2.3
- Acknowledgements
-
Whats New in Python 2.2
- Introduction
- PEPs 252 and 253: Type and Class Changes
- PEP 234: Iterators
- PEP 255: Simple Generators
- PEP 237: Unifying Long Integers and Integers
- PEP 238: Changing the Division Operator
- Unicode Changes
- PEP 227: Nested Scopes
- New and Improved Modules
- Interpreter Changes and Fixes
- Other Changes and Fixes
- Acknowledgements
-
Whats New in Python 2.1
- Introduction
- PEP 227: Nested Scopes
- PEP 236: __future__ Directives
- PEP 207: Rich Comparisons
- PEP 230: Warning Framework
- PEP 229: New Build System
- PEP 205: Weak References
- PEP 232: Function Attributes
- PEP 235: Importing Modules on Case-Insensitive Platforms
- PEP 217: Interactive Display Hook
- PEP 208: New Coercion Model
- PEP 241: Metadata in Python Packages
- New and Improved Modules
- Other Changes and Fixes
- Acknowledgements
-
Whats New in Python 2.0
- Introduction
- What About Python 1.6?
- New Development Process
- Unicode
- List Comprehensions
- Augmented Assignment
- String Methods
- Garbage Collection of Cycles
- Other Core Changes
- Porting to 2.0
- Extending/Embedding Changes
- Distutils: Making Modules Easy to Install
- XML Modules
- Module changes
- New modules
- IDLE Improvements
- Deleted and Deprecated Modules
- Acknowledgements
- Changelog
-
Whats New In Python 3.7
-
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
- Appendix
-
Python Setup and Usage
- Command line and environment
- Using Python on Unix platforms
- Using Python on Windows
- Using Python on a Macintosh
-
The Python Language Reference
- Introduction
- Lexical analysis
-
Data model
- Objects, values and types
- The standard type hierarchy
- Special method names
- Coroutines
- Execution model
- The import system
-
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
- Conditional expressions
- Lambdas
- Expression lists
- Evaluation order
- Operator precedence
- Simple statements
- Compound statements
- Top-level components
- Full Grammar specification
-
The Python Standard Library
- Introduction
- Built-in Functions
- Built-in Constants
-
Built-in Types
- Truth Value Testing
- Boolean Operations and, or, not
- Comparisons
- Numeric Types int, float, complex
- Iterator Types
- Sequence Types list, tuple, range
- Text Sequence Type str
- Binary Sequence Types bytes, bytearray, memoryview
- Set Types set, frozenset
- Mapping Types dict
- Context Manager Types
- Other Built-in Types
- Special Attributes
- Built-in 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
-
Binary Data Services
- struct Interpret bytes as packed binary data
- codecs Codec registry and base classes
-
Data Types
- datetime Basic date and time types
- calendar General calendar-related functions
- collections Container datatypes
- 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
-
enum Support for enumerations
- Module Contents
- 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
- Allowed members and attributes of enumerations
- Restricted Enum subclassing
- Pickling
- Functional API
- Derived Enumerations
- Interesting examples
- How are Enums different?
- Numeric and Mathematical Modules
- Functional Programming Modules
-
File and Directory Access
- pathlib Object-oriented filesystem paths
- os.path Common pathname manipulations
- fileinput Iterate over lines from multiple input streams
- 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
- macpath Mac OS 9 path manipulation functions
-
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
- Data Compression and Archiving
- File Formats
- Cryptographic Services
-
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
- getopt C-style parser for command line options
- logging Logging facility for Python
- logging.config Logging configuration
- logging.handlers Logging handlers
- getpass Portable password input
- curses Terminal handling for character-cell displays
- curses.textpad Text input widget for curses programs
- curses.ascii Utilities for ASCII characters
- curses.panel A panel stack extension for curses
- platform Access to underlying platforms identifying data
- errno Standard errno system symbols
-
ctypes A foreign function library for Python
-
ctypes tutorial
- Loading dynamic link libraries
- Accessing functions from loaded dlls
- Calling functions
- Fundamental data types
- Calling functions, continued
- Calling functions with your own custom data types
- Specifying the required argument types (function prototypes)
- Return types
- 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
-
ctypes tutorial
-
Concurrent Execution
- threading Thread-based parallelism
- multiprocessing Process-based parallelism
- The concurrent package
- concurrent.futures Launching parallel tasks
- subprocess Subprocess management
- sched Event scheduler
- queue A synchronized queue class
- _thread Low-level threading API
- _dummy_thread Drop-in replacement for the _thread module
- dummy_threading Drop-in replacement for the threading module
- contextvars Context Variables
-
Networking and Interprocess Communication
-
asyncio Asynchronous I/O
- Coroutines and Tasks
- Streams
- Synchronization Primitives
- Subprocesses
- Queues
- Exceptions
-
Event Loop
-
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
- Callback Handles
- Server Objects
- Event Loop Implementations
- Examples
-
Event Loop Methods
- Futures
- Transports and Protocols
- Policies
- Platform Support
- High-level API Index
- Low-level API Index
- Developing with asyncio
- socket Low-level networking interface
- ssl TLS/SSL wrapper for socket objects
- select Waiting for I/O completion
- selectors High-level I/O multiplexing
- asyncore Asynchronous socket handler
- asynchat Asynchronous socket command/response handler
- signal Set handlers for asynchronous events
- mmap Memory-mapped file support
-
asyncio Asynchronous I/O
-
Internet Data Handling
-
email An email and MIME handling package
- email.message: Representing an email message
- email.parser: Parsing email messages
- email.generator: Generating MIME documents
- email.policy: Policy Objects
- email.errors: Exception and Defect classes
- email.headerregistry: Custom Header Objects
- email.contentmanager: Managing MIME Content
- email: Examples
- email.message.Message: Representing an email message using the compat32 API
- email.mime: Creating email and MIME objects from scratch
- email.header: Internationalized headers
- email.charset: Representing character sets
- email.encoders: Encoders
- email.utils: Miscellaneous utilities
- email.iterators: Iterators
- json JSON encoder and decoder
- mailcap Mailcap file handling
- mailbox Manipulate mailboxes in various formats
- mimetypes Map filenames to MIME types
- 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
- uu Encode and decode uuencode files
-
email An email and MIME handling package
-
Structured Markup Processing Tools
- html HyperText Markup Language support
- html.parser Simple HTML and XHTML parser
- html.entities Definitions of HTML general entities
- XML Processing Modules
- xml.etree.ElementTree The ElementTree XML API
- xml.dom The Document Object Model API
- xml.dom.minidom Minimal DOM implementation
- xml.dom.pulldom Support for building partial DOM trees
- xml.sax Support for SAX2 parsers
- xml.sax.handler Base classes for SAX handlers
- xml.sax.saxutils SAX Utilities
- xml.sax.xmlreader Interface for XML parsers
- xml.parsers.expat Fast XML parsing using Expat
-
Internet Protocols and Support
- webbrowser Convenient Web-browser controller
- cgi Common Gateway Interface support
- cgitb Traceback manager for CGI scripts
- wsgiref WSGI Utilities and Reference Implementation
- urllib URL handling modules
-
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
- Legacy interface
- urllib.request Restrictions
- urllib.response Response classes used by urllib
- urllib.parse Parse URLs into components
- urllib.error Exception classes raised by urllib.request
- urllib.robotparser Parser for robots.txt
- http HTTP modules
- http.client HTTP protocol client
- ftplib FTP protocol client
- poplib POP3 protocol client
- imaplib IMAP4 protocol client
- nntplib NNTP protocol client
- smtplib SMTP protocol client
- smtpd SMTP Server
- telnetlib Telnet client
- uuid UUID objects according to RFC 4122
- socketserver A framework for network servers
- http.server HTTP servers
- http.cookies HTTP state management
- http.cookiejar Cookie handling for HTTP clients
- xmlrpc XMLRPC server and client modules
- xmlrpc.client XML-RPC client access
- xmlrpc.server Basic XML-RPC servers
- ipaddress IPv4/IPv6 manipulation library
-
Multimedia Services
- audioop Manipulate raw audio data
- aifc Read and write AIFF and AIFC files
- sunau Read and write Sun AU files
- wave Read and write WAV files
- chunk Read IFF chunked data
- colorsys Conversions between color systems
- imghdr Determine the type of an image
- sndhdr Determine type of sound file
- ossaudiodev Access to OSS-compatible audio devices
- Internationalization
-
Program Frameworks
- turtle Turtle graphics
- cmd Support for line-oriented command interpreters
- shlex Simple lexical analysis
-
Graphical User Interfaces with Tk
- tkinter Python interface to Tcl/Tk
- tkinter.ttk Tk themed widgets
- tkinter.tix Extension widgets for Tk
- tkinter.scrolledtext Scrolled Text Widget
- IDLE
- Other Graphical User Interface Packages
-
Development Tools
- typing Support for type hints
- pydoc Documentation generator and online help system
- doctest Test interactive Python examples
- unittest Unit testing framework
- unittest.mock mock object library
-
unittest.mock getting started
- Using Mock
- Patch Decorators
-
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
- Tracking order of calls and less verbose call assertions
- More complex argument matching
- 2to3 - Automated Python 2 to 3 code translation
- test Regression tests package for Python
- test.support Utilities for the Python test suite
- test.support.script_helper Utilities for the Python execution tests
- Debugging and Profiling
- Software Packaging and Distribution
-
Python Runtime Services
- sys System-specific parameters and functions
- sysconfig Provide access to Pythons configuration information
- builtins Built-in objects
- __main__ Top-level script 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
- Custom Python Interpreters
-
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
-
Python Language Services
- parser Access Python parse trees
- ast Abstract Syntax Trees
- symtable Access to the compilers symbol tables
- symbol Constants used with Python parse trees
- token Constants used with Python parse trees
- keyword Testing for Python keywords
- tokenize Tokenizer for Python source
- tabnanny Detection of ambiguous indentation
- pyclbr Python class browser support
- py_compile Compile Python source files
- compileall Byte-compile Python libraries
- dis Disassembler for Python bytecode
- pickletools Tools for pickle developers
- Miscellaneous Services
- MS Windows Specific Services
-
Unix Specific Services
- posix The most common POSIX system calls
- pwd The password database
- spwd The shadow password database
- grp The group database
- crypt Function to check Unix passwords
- termios POSIX style tty control
- tty Terminal control functions
- pty Pseudo-terminal utilities
- fcntl The fcntl and ioctl system calls
- pipes Interface to shell pipelines
- resource Resource usage information
- nis Interface to Suns NIS (Yellow Pages)
- syslog Unix syslog library routines
-
Superseded Modules
-
optparse Parser for command line options
- Background
- Tutorial
- Reference Guide
-
Option Callbacks
- Defining a callback option
- How callbacks are called
- Raising errors in a callback
- Callback example 1: trivial callback
- Callback example 2: check option order
- Callback example 3: check option order (generalized)
- Callback example 4: check arbitrary condition
- Callback example 5: fixed arguments
- Callback example 6: variable arguments
- Extending optparse
- imp Access the import internals
-
optparse Parser for command line options
- Undocumented Modules
-
Extending and Embedding the Python Interpreter
- Recommended third party tools
-
Creating extensions without third party tools
-
Extending Python with C or C++
- A Simple Example
- Intermezzo: Errors and Exceptions
- Back to the Example
- The Modules 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
- Defining Extension Types: Tutorial
- Defining Extension Types: Assorted Topics
- Building C and C++ Extensions
- Building C and C++ Extensions on Windows
-
Extending Python with C or C++
- Embedding the CPython runtime in a larger application
-
Python/C API Reference Manual
- Introduction
- Stable Application Binary Interface
- The Very High Level Layer
- Reference Counting
- Exception Handling
- Utilities
- Abstract Objects Layer
-
Concrete Objects Layer
- Fundamental Objects
- Numeric Objects
- Sequence Objects
- Container Objects
- Function Objects
- Other Objects
-
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
- Memory Management
- Object Implementation Support
- API and ABI Versioning
- Distributing Python Modules
- Installing Python Modules
-
Python HOWTOs
-
Porting Python 2 Code to Python 3
- The Short Explanation
-
Details
- Drop support for Python 2.6 and older
- 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
- Use continuous integration to stay compatible
- Consider using optional static type checking
- Porting Extension Modules to Python 3
- Curses Programming with Python
- Descriptor HowTo Guide
- Functional Programming HOWTO
- Logging HOWTO
-
Logging Cookbook
- Using logging in multiple modules
- Logging from multiple threads
- Multiple handlers and formatters
- Logging to multiple destinations
- Configuration server example
- Dealing with handlers that block
- Sending and receiving logging events across a network
- Adding contextual information to your logging output
- 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()
- Using particular formatting styles throughout your application
- Configuring filters with dictConfig()
- Customized exception formatting
- Speaking logging messages
- Buffering logging messages and outputting them conditionally
- Formatting times using UTC (GMT) via configuration
- Using a context manager for selective logging
- 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
- The Goals Of Argument Clinic
- Basic Concepts And Usage
- Converting Your First Function
-
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
- 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
- Writing a custom converter
- Writing a custom return converter
- METH_O and METH_NOARGS
- tp_new and tp_init functions
- Changing and redirecting Clinics output
- The #ifdef trick
- Using Argument Clinic in Python files
- Instrumenting CPython with DTrace and SystemTap
-
Porting Python 2 Code to Python 3
-
Python Frequently Asked Questions
- General Python FAQ
- Programming FAQ
-
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 cant 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 is join() a string method instead of a list or tuple method?
- How fast are exceptions?
- Why isnt there a switch or case statement in Python?
- Cant you emulate threads in the interpreter instead of relying on an OS-specific thread implementation?
- Why cant lambda expressions contain statements?
- Can Python be compiled to machine code, C or some other language?
- How does Python manage memory?
- Why doesnt CPython use a more traditional garbage collection scheme?
- Why isnt 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 doesnt list.sort() return the sorted list?
- How do you specify and enforce an interface spec in Python?
- Why is there no goto?
- Why cant raw strings (r-strings) end with a backslash?
- Why doesnt Python have a with statement for attribute assignments?
- 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
-
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 call an objects method from C?
- 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?
- 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)?
-
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?
- 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?
- Graphic User Interface FAQ
- Why is Python Installed on my Computer? FAQ
- Glossary
- About these documents
- Dealing with Bugs
- Copyright
- History and License