Python 3.9.5 Language Reference

Python 3.9.5 Language Reference --

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
Generic Alias Type
Other Built-in Types
Special Attributes
Built-in Exceptions
Base classes
Concrete exceptions
Warnings
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
netrc — netrc file processing
xdrlib — Encode and decode XDR data
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 — Provides 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
asyncore — Asynchronous socket handler
asynchat — Asynchronous socket command/response handler
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
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
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
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
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
Other Graphical User Interface Packages
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 — 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
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 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
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
Using importlib.metadata
Python Language Services
parser — Access Python parse trees
ast — Abstract Syntax Trees
symtable — Access to the compiler’s 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 module 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
formatter — Generic output formatting
MS Windows Specific Services
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
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 Sun’s NIS (Yellow Pages)
syslog — Unix syslog library routines
Superseded Modules
optparse — Parser for command line options
imp — Access the import internals
Undocumented Modules
Platform specific modules