What’s in which Python

Created 17 May 2022, last updated 19 May 2022

This is a summary of what features appeared in which versions of Python. Items with a star were introduced with a __future__ import.

3.11 (beta): due October 3, 2022

• 10–60% faster than 3.10
• exact expression error locations
• exception groups and notes
• typing: Self (PEP 673), LiteralString (PEP 675), variadic generics (PEP 646)

Full list of 3.11 changes so far.

3.10: October 4, 2021

• structural pattern matching (PEP 634)
• better error messages
• parenthesized context managers
• union types as X|Y

Full list of 3.10 changes.

3.9: October 5, 2020

• dict union operators
• type hinting generics in standard collections
• relaxed decorator syntax
• str.removeprefix and str.removesuffix

Full list of 3.9 changes.

3.8: October 14, 2019

• assignment expressions (walrus operator := )
• f-string “=” specifier
• positional-only parameters

Full list of 3.8 changes.

3.7: June 27, 2018

• postponed evaluation of type annotations (PEP 563)
• async and await are keywords
• dataclasses
• dict order is guaranteed

Full list of 3.7 changes.

3.6: December 23, 2016

• f-strings
• kwargs and class attributes order is preserved
• dicts happen to be (but are not guaranteed to be) ordered
• underscores in numeric literals
• variable annotations
• secrets module in stdlib

Full list of 3.6 changes.

3.5: September 13, 2015

• async and await syntax
• matrix multiplication operator @
• more unpacking generalizations
• The typing module for type hints
• subprocess.run()
• os.scandir()

Full list of 3.5 changes.

3.4: March 16, 2014

• pip is always available, via ensurepip
• asyncio (provisional API)
• Other stdlib modules: statistics, pathlib, and tracemalloc

Full list of 3.4 changes.

3.3: September 29th, 2012

• yield from
• u”” literals are back
• unittest.mock
• hash randomization
• New flexible string representation
• venv module
• more of import implemented in Python

Full list of 3.3 changes.

3.2: February 20th, 2011

• argparse
• concurrent.futures
• __pycache__ directories
• hasattr doesn’t swallow all exceptions

Full list of 3.2 changes.

3.1: June 27th, 2009

• OrderedDict and Counter classes
• __main__.py

Full list of 3.1 changes.

3.0: December 3rd, 2008

• strings are now unicode, no u”” literals
• print as a function
• iterators instead of lists: range, .keys, .items, .values, zip, map, filter
• nonlocal
• function annotations
• lots of things moved in the standard library

Full list of 3.0 changes.

2.7: July 3rd, 2010

• Set literals syntax
• Dictionary and set comprehensions
• OrderedDict and Counter classes
• argparse
• .format can use bare {} placeholders

Full list of 2.7 changes.

2.6: October 1st, 2008

• The multiprocessing package
• str.format()
• 3.0 compatibility: print function *, byte literals, io library
• “except” with “as” keyword
• Abstract base classes
• Class decorators
• The fractions module

Full list of 2.6 changes.

2.5: September 19th, 2006

• The “with” statement *
• Conditional expressions
• The functools module
• Unified try/except/finally
• Value passed into generators
• defaultdict
• any(), all(), min(key=) and max(key=)

Full list of 2.5 changes.

2.4: November 30th, 2004

• Native set datatype
• Generator expressions
• Function decorators
• string.Template
• reversed()
• The subprocess and decimal modules

Full list of 2.4 changes.

2.3: July 29th, 2003

• Set datatype module
• Boolean datatype
• Importing from zip files
• enumerate
• The logging and csv packages
• Extended list slicing

Full list of 2.3 changes.

2.2: December 21st, 2001

• New-style classes
• Iterators
• Generators *
• // integer division
• Dividing ints can produce floats *

Full list of 2.2 changes.

2.1: April 17th, 2001

• Nested scopes *
• “from __future__”
• Rich comparisons
• Weak references

Full list of 2.1 changes.