The Python Standard Library
While The Python Language Reference describes the exact syntax and semantics of the Python language, this library reference manual describes the standard library that is distributed with Python. It also describes some of the optional components that are commonly included in Python distributions.
Python’s standard library is very extensive, offering a wide range of facilities as indicated by the long table of contents listed below. The library contains built-in modules (written in C) that provide access to system functionality such as file I/O that would otherwise be inaccessible to Python programmers, as well as modules written in Python that provide standardized solutions for many problems that occur in everyday programming. Some of these modules are explicitly designed to encourage and enhance the portability of Python programs by abstracting away platform-specifics into platform-neutral APIs.
The Python installers for the Windows platform usually include the entire standard library and often also include many additional components. For Unix-like operating systems Python is normally provided as a collection of packages, so it may be necessary to use the packaging tools provided with the operating system to obtain some or all of the optional components.
In addition to the standard library, there is a growing collection of several thousand components (from individual programs and modules to packages and entire application development frameworks), available from the Python Package Index.
- 1. Introduction
- 2. Built-in Functions
- 3. Built-in Constants
- 4. Built-in Types
- 4.1. Truth Value Testing
- 4.2. Boolean Operations —
and,or,not - 4.3. Comparisons
- 4.4. Numeric Types —
int,float,complex - 4.5. Iterator Types
- 4.6. Sequence Types —
list,tuple,range - 4.7. Text Sequence Type —
str - 4.8. Binary Sequence Types —
bytes,bytearray,memoryview - 4.9. Set Types —
set,frozenset - 4.10. Mapping Types —
dict - 4.11. Context Manager Types
- 4.12. Other Built-in Types
- 4.13. Special Attributes
- 5. Built-in Exceptions
- 6. Text Processing Services
- 6.1.
string— Common string operations - 6.2.
re— Regular expression operations - 6.3.
difflib— Helpers for computing deltas - 6.4.
textwrap— Text wrapping and filling - 6.5.
unicodedata— Unicode Database - 6.6.
stringprep— Internet String Preparation - 6.7.
readline— GNU readline interface - 6.8.
rlcompleter— Completion function for GNU readline
- 6.1.
- 7. Binary Data Services
- 8. Data Types
- 8.1.
datetime— Basic date and time types - 8.2.
calendar— General calendar-related functions - 8.3.
collections— Container datatypes - 8.4.
collections.abc— Abstract Base Classes for Containers - 8.5.
heapq— Heap queue algorithm - 8.6.
bisect— Array bisection algorithm - 8.7.
array— Efficient arrays of numeric values - 8.8.
weakref— Weak references - 8.9.
types— Dynamic type creation and names for built-in types - 8.10.
copy— Shallow and deep copy operations - 8.11.
pprint— Data pretty printer - 8.12.
reprlib— Alternaterepr()implementation - 8.13.
enum— Support for enumerations
- 8.1.
- 9. Numeric and Mathematical Modules
- 9.1.
numbers— Numeric abstract base classes - 9.2.
math— Mathematical functions - 9.3.
cmath— Mathematical functions for complex numbers - 9.4.
decimal— Decimal fixed point and floating point arithmetic - 9.5.
fractions— Rational numbers - 9.6.
random— Generate pseudo-random numbers - 9.7.
statistics— Mathematical statistics functions
- 9.1.
- 10. Functional Programming Modules
- 11. File and Directory Access
- 11.1.
pathlib— Object-oriented filesystem paths - 11.2.
os.path— Common pathname manipulations - 11.3.
fileinput— Iterate over lines from multiple input streams - 11.4.
stat— Interpretingstat()results - 11.5.
filecmp— File and Directory Comparisons - 11.6.
tempfile— Generate temporary files and directories - 11.7.
glob— Unix style pathname pattern expansion - 11.8.
fnmatch— Unix filename pattern matching - 11.9.
linecache— Random access to text lines - 11.10.
shutil— High-level file operations - 11.11.
macpath— Mac OS 9 path manipulation functions
- 11.1.
- 12. Data Persistence
- 13. Data Compression and Archiving
- 14. File Formats
- 15. Cryptographic Services
- 16. Generic Operating System Services
- 16.1.
os— Miscellaneous operating system interfaces - 16.2.
io— Core tools for working with streams - 16.3.
time— Time access and conversions - 16.4.
argparse— Parser for command-line options, arguments and sub-commands - 16.5.
getopt— C-style parser for command line options - 16.6.
logging— Logging facility for Python - 16.7.
logging.config— Logging configuration - 16.8.
logging.handlers— Logging handlers - 16.9.
getpass— Portable password input - 16.10.
curses— Terminal handling for character-cell displays - 16.11.
curses.textpad— Text input widget for curses programs - 16.12.
curses.ascii— Utilities for ASCII characters - 16.13.
curses.panel— A panel stack extension for curses - 16.14.
platform— Access to underlying platform’s identifying data - 16.15.
errno— Standard errno system symbols - 16.16.
ctypes— A foreign function library for Python
- 16.1.
- 17. Concurrent Execution
- 17.1.
threading— Thread-based parallelism - 17.2.
multiprocessing— Process-based parallelism - 17.3. The
concurrentpackage - 17.4.
concurrent.futures— Launching parallel tasks - 17.5.
subprocess— Subprocess management - 17.6.
sched— Event scheduler - 17.7.
queue— A synchronized queue class - 17.8.
_thread— Low-level threading API - 17.9.
_dummy_thread— Drop-in replacement for the_threadmodule - 17.10.
dummy_threading— Drop-in replacement for thethreadingmodule
- 17.1.
- 18. Interprocess Communication and Networking
- 18.1.
socket— Low-level networking interface - 18.2.
ssl— TLS/SSL wrapper for socket objects - 18.3.
select— Waiting for I/O completion - 18.4.
selectors— High-level I/O multiplexing - 18.5.
asyncio— Asynchronous I/O, event loop, coroutines and tasks - 18.6.
asyncore— Asynchronous socket handler - 18.7.
asynchat— Asynchronous socket command/response handler - 18.8.
signal— Set handlers for asynchronous events - 18.9.
mmap— Memory-mapped file support
- 18.1.
- 19. Internet Data Handling
- 19.1.
email— An email and MIME handling package - 19.2.
json— JSON encoder and decoder - 19.3.
mailcap— Mailcap file handling - 19.4.
mailbox— Manipulate mailboxes in various formats - 19.5.
mimetypes— Map filenames to MIME types - 19.6.
base64— Base16, Base32, Base64, Base85 Data Encodings - 19.7.
binhex— Encode and decode binhex4 files - 19.8.
binascii— Convert between binary and ASCII - 19.9.
quopri— Encode and decode MIME quoted-printable data - 19.10.
uu— Encode and decode uuencode files
- 19.1.
- 20. Structured Markup Processing Tools
- 20.1.
html— HyperText Markup Language support - 20.2.
html.parser— Simple HTML and XHTML parser - 20.3.
html.entities— Definitions of HTML general entities - 20.4. XML Processing Modules
- 20.5.
xml.etree.ElementTree— The ElementTree XML API - 20.6.
xml.dom— The Document Object Model API - 20.7.
xml.dom.minidom— Minimal DOM implementation - 20.8.
xml.dom.pulldom— Support for building partial DOM trees - 20.9.
xml.sax— Support for SAX2 parsers - 20.10.
xml.sax.handler— Base classes for SAX handlers - 20.11.
xml.sax.saxutils— SAX Utilities - 20.12.
xml.sax.xmlreader— Interface for XML parsers - 20.13.
xml.parsers.expat— Fast XML parsing using Expat
- 20.1.
- 21. Internet Protocols and Support
- 21.1.
webbrowser— Convenient Web-browser controller - 21.2.
cgi— Common Gateway Interface support - 21.3.
cgitb— Traceback manager for CGI scripts - 21.4.
wsgiref— WSGI Utilities and Reference Implementation - 21.5.
urllib— URL handling modules - 21.6.
urllib.request— Extensible library for opening URLs - 21.7.
urllib.response— Response classes used by urllib - 21.8.
urllib.parse— Parse URLs into components - 21.9.
urllib.error— Exception classes raised by urllib.request - 21.10.
urllib.robotparser— Parser for robots.txt - 21.11.
http— HTTP modules - 21.12.
http.client— HTTP protocol client - 21.13.
ftplib— FTP protocol client - 21.14.
poplib— POP3 protocol client - 21.15.
imaplib— IMAP4 protocol client - 21.16.
nntplib— NNTP protocol client - 21.17.
smtplib— SMTP protocol client - 21.18.
smtpd— SMTP Server - 21.19.
telnetlib— Telnet client - 21.20.
uuid— UUID objects according to RFC 4122 - 21.21.
socketserver— A framework for network servers - 21.22.
http.server— HTTP servers - 21.23.
http.cookies— HTTP state management - 21.24.
http.cookiejar— Cookie handling for HTTP clients - 21.25.
xmlrpc— XMLRPC server and client modules - 21.26.
xmlrpc.client— XML-RPC client access - 21.27.
xmlrpc.server— Basic XML-RPC servers - 21.28.
ipaddress— IPv4/IPv6 manipulation library
- 21.1.
- 22. Multimedia Services
- 22.1.
audioop— Manipulate raw audio data - 22.2.
aifc— Read and write AIFF and AIFC files - 22.3.
sunau— Read and write Sun AU files - 22.4.
wave— Read and write WAV files - 22.5.
chunk— Read IFF chunked data - 22.6.
colorsys— Conversions between color systems - 22.7.
imghdr— Determine the type of an image - 22.8.
sndhdr— Determine type of sound file - 22.9.
ossaudiodev— Access to OSS-compatible audio devices
- 22.1.
- 23. Internationalization
- 24. Program Frameworks
- 25. Graphical User Interfaces with Tk
- 26. Development Tools
- 26.1.
typing— Support for type hints - 26.2.
pydoc— Documentation generator and online help system - 26.3.
doctest— Test interactive Python examples - 26.4.
unittest— Unit testing framework - 26.5.
unittest.mock— mock object library - 26.6.
unittest.mock— getting started - 26.7. 2to3 - Automated Python 2 to 3 code translation
- 26.8.
test— Regression tests package for Python - 26.9.
test.support— Utilities for the Python test suite
- 26.1.
- 27. Debugging and Profiling
- 28. Software Packaging and Distribution
- 29. Python Runtime Services
- 29.1.
sys— System-specific parameters and functions - 29.2.
sysconfig— Provide access to Python’s configuration information - 29.3.
builtins— Built-in objects - 29.4.
__main__— Top-level script environment - 29.5.
warnings— Warning control - 29.6.
contextlib— Utilities forwith-statement contexts - 29.7.
abc— Abstract Base Classes - 29.8.
atexit— Exit handlers - 29.9.
traceback— Print or retrieve a stack traceback - 29.10.
__future__— Future statement definitions - 29.11.
gc— Garbage Collector interface - 29.12.
inspect— Inspect live objects - 29.13.
site— Site-specific configuration hook
- 29.1.
- 30. Custom Python Interpreters
- 31. Importing Modules
- 32. Python Language Services
- 32.1.
parser— Access Python parse trees - 32.2.
ast— Abstract Syntax Trees - 32.3.
symtable— Access to the compiler’s symbol tables - 32.4.
symbol— Constants used with Python parse trees - 32.5.
token— Constants used with Python parse trees - 32.6.
keyword— Testing for Python keywords - 32.7.
tokenize— Tokenizer for Python source - 32.8.
tabnanny— Detection of ambiguous indentation - 32.9.
pyclbr— Python class browser support - 32.10.
py_compile— Compile Python source files - 32.11.
compileall— Byte-compile Python libraries - 32.12.
dis— Disassembler for Python bytecode - 32.13.
pickletools— Tools for pickle developers
- 32.1.
- 33. Miscellaneous Services
- 34. MS Windows Specific Services
- 35. Unix Specific Services
- 35.1.
posix— The most common POSIX system calls - 35.2.
pwd— The password database - 35.3.
spwd— The shadow password database - 35.4.
grp— The group database - 35.5.
crypt— Function to check Unix passwords - 35.6.
termios— POSIX style tty control - 35.7.
tty— Terminal control functions - 35.8.
pty— Pseudo-terminal utilities - 35.9.
fcntl— Thefcntlandioctlsystem calls - 35.10.
pipes— Interface to shell pipelines - 35.11.
resource— Resource usage information - 35.12.
nis— Interface to Sun’s NIS (Yellow Pages) - 35.13.
syslog— Unix syslog library routines
- 35.1.
- 36. Superseded Modules
- 37. Undocumented Modules