STD Lib Python

Built-in Functions Built-in Constants

Constants added by the site module

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 Type Annotation Types — Generic Alias, Union Other Built-in Types Special Attributes Integer string conversion length limitation

Built-in Exceptions

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

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 zoneinfo — IANA time zone support 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 graphlib — Functionality to operate with graph-like structures

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

Functional Programming Modules

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

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

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

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

File Formats

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

Cryptographic Services

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

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 platform’s identifying data errno — Standard errno system symbols ctypes — A foreign function library for Python

Concurrent Execution

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

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

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 binascii — Convert between binary and ASCII quopri — Encode and decode MIME quoted-printable data

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 wsgiref — WSGI Utilities and Reference Implementation urllib — URL handling modules urllib.request — Extensible library for opening URLs 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 smtplib — SMTP protocol 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

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

Internationalization

gettext — Multilingual internationalization services locale — Internationalization services

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.colorchooser — Color choosing dialog tkinter.font — Tkinter font wrapper Tkinter Dialogs tkinter.messagebox — Tkinter message prompts tkinter.scrolledtext — Scrolled Text Widget tkinter.dnd — Drag and drop support tkinter.ttk — Tk themed widgets tkinter.tix — Extension widgets for Tk IDLE

Development Tools

typing — Support for type hints pydoc — Documentation generator and online help system Python Development Mode doctest — Test interactive Python examples unittest — Unit testing framework unittest.mock — mock object library 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.socket_helper — Utilities for socket tests test.support.script_helper — Utilities for the Python execution tests test.support.bytecode_helper — Support tools for testing correct bytecode generation test.support.threading_helper — Utilities for threading tests test.support.os_helper — Utilities for os tests test.support.import_helper — Utilities for import tests test.support.warnings_helper — Utilities for warnings tests

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

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

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

Custom Python Interpreters

code — Interpreter base classes codeop — Compile Python code

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 importlib.resources – Package resource reading, opening and access importlib.resources.abc – Abstract base classes for resources importlib.metadata – Accessing package metadata The initialization of the sys.path module search path

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

MS Windows Specific Services

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

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

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) 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

Security Considerations