Python 3 Standard Library

Overview Articles

Python 3 Standard Library Reference

A gateway to the Python Standard Library reference material.

Articles by Category

asynchronous i/o

asyncio — Asynchronous I/O

Coroutines and Tasks

Developing with asyncio

High-level API Index

Low-level API Index

Platform Support

Synchronization Primitives

Transports and Protocols

binary data

codecs — Codec registry and base classes

struct — Interpret bytes as packed binary data

built-in constants

Built-in Constants

built-in exceptions

Built-in Exceptions

built-in functions

Built-in Functions

built-in types

concurrent execution

_thread — Low-level threading API

concurrent.futures — Launching parallel tasks

contextvars — Context Variables

multiprocessing — Process-based parallelism

multiprocessing.shared_memory — Provides shared memory for direct access across processes

queue — A synchronized queue class

sched — Event scheduler

subprocess — Subprocess management

The concurrent package

threading — Thread-based parallelism

cryptography

hashlib — Secure hashes and message digests

hmac — Keyed-Hashing for Message Authentication

secrets — Generate secure random numbers for managing secrets

data compression

bz2 — Support for bzip2 compression

gzip — Support for gzip files

lzma — Compression using the LZMA algorithm

tarfile — Read and write tar archive files

zipfile — Work with ZIP archives

zlib — Compression compatible with gzip

data persistence

copyreg — Register pickle support functions

dbm — Interfaces to Unix “databases”

marshal — Internal Python object serialization

pickle — Python object serialization

shelve — Python object persistence

sqlite3 — DB-API 2.0 interface for SQLite databases

data types

array — Efficient arrays of numeric values

bisect — Array bisection algorithm

calendar — General calendar-related functions

collections — Container datatypes

collections.abc — Abstract Base Classes for Containers

copy — Shallow and deep copy operations

datetime — Basic date and time types

enum — Support for enumerations

graphlib — Functionality to operate with graph-like structures

heapq — Heap queue algorithm

pprint — Data pretty printer

reprlib — Alternate repr() implementation

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

weakref — Weak references

zoneinfo — IANA time zone support

debugging & 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

development tools

doctest — Test interactive Python examples

pydoc — Documentation generator and online help system

Python Development Mode

test — Regression tests package for Python

typing — Support for type hints

unittest — Unit testing framework

unittest.mock — mock object library

email

email.charset: Representing character sets

email.contentmanager: Managing MIME Content

email.encoders: Encoders

email.errors: Exception and Defect classes

email.generator: Generating MIME documents

email.header: Internationalized headers

email.headerregistry: Custom Header Objects

email.iterators: Iterators

email.message.Message: Representing an email message using the compat32 API

email.message: Representing an email message

email.mime: Creating email and MIME objects from scratch

email.parser: Parsing email messages

email.policy: Policy Objects

email.utils: Miscellaneous utilities

email: Examples

file & directory access

File and Directory Access

filecmp — File and Directory Comparisons

fileinput — Iterate over lines from multiple input streams

fnmatch — Unix filename pattern matching

glob — Unix style pathname pattern expansion

linecache — Random access to text lines

os.path — Common pathname manipulations

pathlib — Object-oriented filesystem paths

shutil — High-level file operations

stat — Interpreting stat() results

tempfile — Generate temporary files and directories

file formats

configparser — Configuration file parser

csv — CSV File Reading and Writing

netrc — netrc file processing

plistlib — Generate and parse Apple .plist files

xdrlib — Encode and decode XDR data

frameworks

cmd — Support for line-oriented command interpreters

shlex — Simple lexical analysis

turtle — Turtle graphics

functional programming

functools — Higher-order functions and operations on callable objects

itertools — Functions creating iterators for efficient looping

operator — Standard operators as functions

importing

importlib — The implementation of import

modulefinder — Find modules used by a script

pkgutil — Package extension utility

runpy — Locating and executing Python modules

Using importlib.metadata

zipimport — Import modules from Zip archives

input/ouput

select — Waiting for I/O completion

selectors — High-level I/O multiplexing

internationalization

gettext — Multilingual internationalization services

locale — Internationalization services

internet

cgi — Common Gateway Interface support

cgitb — Traceback manager for CGI scripts

ftplib — FTP protocol client

http — HTTP modules

http.client — HTTP protocol client

http.cookiejar — Cookie handling for HTTP clients

http.cookies — HTTP state management

http.server — HTTP servers

imaplib — IMAP4 protocol client

ipaddress — IPv4/IPv6 manipulation library

nntplib — NNTP protocol client

poplib — POP3 protocol client

smtpd — SMTP Server

smtplib — SMTP protocol client

socketserver — A framework for network servers

telnetlib — Telnet client

urllib — URL handling modules

urllib.error — Exception classes raised by urllib.request

urllib.parse — Parse URLs into components

urllib.request — Extensible library for opening URLs

urllib.robotparser — Parser for robots.txt

uuid — UUID objects according to RFC 4122

webbrowser — Convenient Web-browser controller

wsgiref — WSGI Utilities and Reference Implementation

xmlrpc — XMLRPC server and client modules

xmlrpc.client — XML-RPC client access

xmlrpc.server — Basic XML-RPC servers

internet data

base64 — Base16, Base32, Base64, Base85 Data Encodings

binascii — Convert between binary and ASCII

binhex — Encode and decode binhex4 files

email — An email and MIME handling package

json — JSON encoder and decoder

mailbox — Manipulate mailboxes in various formats

mailcap — Mailcap file handling

mimetypes — Map filenames to MIME types

quopri — Encode and decode MIME quoted-printable data

uu — Encode and decode uuencode files

interpreters

code — Interpreter base classes

codeop — Compile Python code

language

ast — Abstract Syntax Trees

compileall — Byte-compile Python libraries

dis — Disassembler for Python bytecode

keyword — Testing for Python keywords

parser — Access Python parse trees

pickletools — Tools for pickle developers

py_compile — Compile Python source files

pyclbr — Python module browser support

symbol — Constants used with Python parse trees

symtable — Access to the compiler’s symbol tables

tabnanny — Detection of ambiguous indentation

token — Constants used with Python parse trees

tokenize — Tokenizer for Python source

logging

logging — Logging facility for Python

logging.config — Logging configuration

logging.handlers — Logging handlers

ms windows

msilib — Read and write Microsoft Installer files

msvcrt — Useful routines from the MS VC++ runtime

winreg — Windows registry access

winsound — Sound-playing interface for Windows

multimedia

aifc — Read and write AIFF and AIFC files

audioop — Manipulate raw audio data

chunk — Read IFF chunked data

colorsys — Conversions between color systems

imghdr — Determine the type of an image

ossaudiodev — Access to OSS-compatible audio devices

sndhdr — Determine type of sound file

wave — Read and write WAV files

networking & interprocess communication

asynchat — Asynchronous socket command/response handler

asyncore — Asynchronous socket handler

mmap — Memory-mapped file support

signal — Set handlers for asynchronous events

socket — Low-level networking interface

ssl — TLS/SSL wrapper for socket objects

numeric & mathematical

cmath — Mathematical functions for complex numbers

decimal — Decimal fixed point and floating point arithmetic

fractions — Rational numbers

math — Mathematical functions

numbers — Numeric abstract base classes

random — Generate pseudo-random numbers

statistics — Mathematical statistics functions

operating system

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

ctypes — A foreign function library for Python

curses — Terminal handling for character-cell displays

curses.ascii — Utilities for ASCII characters

curses.panel — A panel stack extension for curses

errno — Standard errno system symbols

getopt — C-style parser for command line options

getpass — Portable password input

io — Core tools for working with streams

os — Miscellaneous operating system interfaces

platform — Access to underlying platform’s identifying data

time — Time access and conversions

runtime

__future__ — Future statement definitions

__main__ — Top-level script environment

abc — Abstract Base Classes

atexit — Exit handlers

builtins — Built-in objects

contextlib — Utilities for with-statement contexts

dataclasses — Data Classes

gc — Garbage Collector interface

inspect — Inspect live objects

site — Site-specific configuration hook

sys — System-specific parameters and functions

sysconfig — Provide access to Python’s configuration information

traceback — Print or retrieve a stack traceback

warnings — Warning control

software packaging & distribution

distutils — Building and installing Python modules

ensurepip — Bootstrapping the pip installer

venv — Creation of virtual environments

zipapp — Manage executable Python zip archives

structured markup

html — HyperText Markup Language support

html.entities — Definitions of HTML general entities

html.parser — Simple HTML and XHTML parser

XML Processing Modules

xml.dom — The Document Object Model API

xml.dom.minidom — Minimal DOM implementation

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

xml.etree.ElementTree — The ElementTree XML API

xml.parsers.expat — Fast XML parsing using Expat

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

text processing

difflib — Helpers for computing deltas

re — Regular expression operations

readline — GNU readline interface

rlcompleter — Completion function for GNU readline

string — Common string operations

stringprep — Internet String Preparation

textwrap — Text wrapping and filling

unicodedata — Unicode Database

tk

Other Graphical User Interface Packages

tkinter — Python interface to Tcl/Tk

Tkinter Dialogs

tkinter.colorchooser — Color choosing dialog

tkinter.dnd — Drag and drop support

tkinter.font — Tkinter font wrapper

tkinter.messagebox — Tkinter message prompts

tkinter.scrolledtext — Scrolled Text Widget

tkinter.tix — Extension widgets for Tk

tkinter.ttk — Tk themed widgets

unix

crypt — Function to check Unix passwords

fcntl — The fcntl and ioctl system calls

grp — The group database

nis — Interface to Sun’s NIS (Yellow Pages)

pipes — Interface to shell pipelines

posix — The most common POSIX system calls

pty — Pseudo-terminal utilities

pwd — The password database

resource — Resource usage information

spwd — The shadow password database

syslog — Unix syslog library routines

termios — POSIX style tty control

tty — Terminal control functions