Python

home	https://www.python.org/
wiki	https://en.wikipedia.org/wiki/Python_(programming_language)

Language

#!/usr/bin/env python3
def main():
    print("Hello World!")

if __name__ == '__main__':
    main()

1991-
Author: Guido van Rossum
PEP - Python Enhancement Proposals
.format() https://pyformat.info/
f"string" https://fstring.help/

Changelog

year	ver	usage	PEP	description
2015	3.5	typing package	0484	type hints
		zipapp package	0441	.pyz a way to package source code
		mat1 @ mat2	0465	matrix multiplication
		async/await	0492	coroutines with async and await syntax
		*[1, 2] => 1, 2	0448	additional unpacking generalizations
		**{'a': 1, 'c': 3} => a=1, c=3		aka splat operator
2016	3.6	f"hello {name}"	0498	formatted string literals
		1_000_000	0515	underscores in numeric literals
		captain: string	0526	type annotations(aka hints) for variables
		can use await and yield on 1 async function	0525	asynchronous generators
		[ i async for i in aiter() if i % 2]	0530	asynchronous comprehensions
		[await fun() for fun in functs if await cond()]
		secrets package	0506
2018	3.7	breakpoint()
		__getattr__	0562
		_ns	0564
		dicts remember insertion
		@dataclass	0567
		importlib.resources
2019	3.8	(:=) "walrus operator"	0572	assignment as an expression
		@functor.cached_property
		importlib.metadata
		typing.TypedDict		specify the keys
		typing.Final		mark as a constant
		typing.Literal
		f'{name=}'		print the name and value
		(, /) positional only parameters	0570	forbids explicitly passing the name
2020	3.9	parser from LLI to PEG	0617
		zoneinfo package
		¦ dictionary merge
		¦= dictionary update
		str.removesuffix()
		str.removeprefix()
		generic typing.Dict as dict	0585
		generic typing.List as list
2021	3.10	match/case	0634	a sort of "switch"
		with (ctx1() as e1, ctx2() as e2):		parentheses on with context managers
		(int ¦ float) instead of typing.Union[int,float]	0604	type union operator
		statistics.(covariance/correlation/lregression)
2022	3.11	tomllib package		to read toml files, like pyproject.toml
		x: NotRequired[str]	0655	for potentially missing keys on a TypedDict
		x: Required[str]
		LiteralString type	0675	raises and error if the string is not static
		.add_not() to all exceptions	0678	to enrich exceptions without raise another

Decorators (@)

@classmethod	def
@dataclass	class

Special Methods

https://docs.python.org/3/reference/datamodel.html#object.__setitem__

	2nd	3rd	4th	Description
__init__()				constructor
__call__()	x
__bool__()
__hash__()
__enter__()				with statement context manager
__exit__()	exc_type	exc_value	traceback
__eq__()	other
__lt__()	other
__gt__()	other
__repr__()				unambiguous representation
__str__()				readable representation
__len__()				len(a)
__getitem__()	index			a[n]
__setitem__()	index	element
__contains__()	element
__reversed__()
__getattribute__()	name
__getattr__()	name
__setattr__()	name	value
__delattr__()	name
__iter__()				iterator
__next__()				iterator
__add__()	other			emulating numeric types
__sub__()	other

Style

Type Hints

PEP 484 – Type Hints https://peps.python.org/pep-0484/
PEP 483 – The Theory of Type Hints https://peps.python.org/pep-0483/
PEP 482 – Literature Overview for Type Hints https://peps.python.org/pep-0482/

Standard Library

Binary Data Services

struct	Interpret bytes as packed binary data
codecs	Codec registry and base classes

Concurrent Execution

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

Cryptographic Services

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

Data Compression and Archiving

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

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

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

Functional Programming Modules

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

Generic Operating System Services

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
curses.textpad	Text input widget for curses programs
errno	Standard errno system symbols
getopt	C-style parser for command line options
getpass	Portable password input
io	Core tools for working with streams
logging	Logging facility for Python
logging.config	Logging configuration
logging.handlers	Logging handlers
os	Miscellaneous operating system interfaces
platform	Access to underlying platform’s identifying data
time	Time access and conversions

Graphical User Interfaces with Tk

tkinter	Python interface to Tcl/Tk
tkinter.colorchooser	Color choosing dialog
tkinter.font	Tkinter font wrapper
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

Importing Modules

importlib	The implementation of import
modulefinder	Find modules used by a script
pkgutil	Package extension utility
runpy	Locating and executing Python modules
zipimport	Import modules from Zip archives

Internationalization

gettext	Multilingual internationalization services
locale	Internationalization services

Internet Data Handling

binascii	Convert between binary and ASCII
base64	Base16, Base32, Base64, Base85 Data Encodings
email	An email and MIME handling package
json	JSON encoder and decoder
mailbox	Manipulate mailboxes in various formats
mimetypes	Map filenames to MIME types
quopri	Encode and decode MIME quoted-printable data

Internet Protocols and Support

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
poplib	POP3 protocol client
smtplib	SMTP protocol client
socketserver	A framework for network servers
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.response	Response classes used by urllib
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

Multimedia Services

wave	Read and write WAV files
colorsys	Conversions between color systems

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

Numeric and Mathematical Modules

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

Program Frameworks

turtle	Turtle graphics
cmd	Support for line-oriented command interpreters
shlex	Simple lexical analysis

Python Runtime Services

abc	Abstract Base Classes
atexit	Exit handlers
builtins	Built-in objects
contextlib	Utilities for with-statement contexts
dataclasses	Data Classes
__future__	Future statement definitions
gc	Garbage Collector interface
inspect	Inspect live objects
__main__	Top-level code environment
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

Structured Markup Processing Tools

html	HyperText Markup Language support
html.parser	Simple HTML and XHTML parser
html.entities	Definitions of HTML general entities
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

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

Text Processing Services

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

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

MS Windows Specific Services

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

dev / test / debug

Custom Python Interpreters

code	Interpreter base classes
codeop	Compile Python code

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
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

bdb	Debugger framework
faulthandler	Dump the Python traceback
pdb	The Python Debugger
timeit	Measure execution time of small code snippets
trace	Trace or track Python statement execution
tracemalloc	Trace memory allocations

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

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