.. _history:

+++++++++++++++++
History of Python
+++++++++++++++++

Guido van Rossum started to write Python in December 1989.

See also :ref:`Python Development Workflow <workflow>`.

History of Python releases
==========================

See also `Status of Python branches
<https://docs.python.org/devguide/#status-of-python-branches>`_.

* Python 3.11: October 2022
* Python 3.10: October 2021
* Python 3.9: October 2020
* Python 3.8: October 2019
* Python 3.7: June 2018
* Python 3.6: December 2016
* Python 3.5: September 2015
* Python 3.4: March 2014
* Python 3.3: September 2012
* Python 3.2: February 2011
* Python 2.7: July 2010
* Python 3.1: June 2009
* Python 3.0: December 2008
* Python 2.6: October 2008
* Python 2.5: September 2006
* Python 2.4: March 2005
* Python 2.3: July 2003
* Python 2.2: December 2001
* Python 2.1: April 2001
* Python 2.0: October 2000
* Python 1.5: April 1999
* Python 0.9.1: `February 20, 1991
  <https://www.tuhs.org/Usenet/alt.sources/1991-February/001749.html>`_
  (date commonly used at the birth of the Python project)



History of the Python language (syntax)
=======================================

* Python 3.8: ``x := 1`` assignment expression (PEP 572) and ``/`` in function
  for positional-only parameters (PEP 570)
* Python 3.7: ``async`` and ``await`` become keywords
* Python 3.6: f-strings (`PEP 498 "Literal String Interpolation"
  <https://www.python.org/dev/peps/pep-0498/>`_)
* Python 3.5:

  * Add ``async`` and ``await`` (not really keywords yet)
  * The ``@`` operator (`PEP 465 "A dedicated infix operator for matrix multiplication"
    <https://www.python.org/dev/peps/pep-0465/>`_)
  * `PEP 448 "Additional Unpacking Generalization" <https://www.python.org/dev/peps/pep-0448/>`_

* *(Python 3.4: no change)*
* Python 3.3:

  * ``yield from``: `PEP 380 "Syntax for Delegating to a Subgenerator"
    <http://legacy.python.org/dev/peps/pep-0380/>`_
  * ``u'unicode'`` syntax is back: `PEP 414 "Explicit Unicode literals"
    <http://legacy.python.org/dev/peps/pep-0414/>`_

* *(Python 3.2: no change)*
* Python 2.7:

  * all changes of Python 3.1

* Python 3.1:

  * dict/set comprehension
  * set literals
  * multiple context managers in a single with statement

* Python 3.0:

  * all changes of Python 2.6
  * new ``nonlocal`` keyword
  * ``raise exc from exc2``: `PEP 3134 "Exception Chaining and Embedded
    Tracebacks" <http://legacy.python.org/dev/peps/pep-3134/>`_
  * ``print`` and ``exec`` become a function
  * ``True``, ``False``, ``None``, ``as``, ``with`` are reserved words
  * Change from ``except exc, var`` to ``except exc as var``:
    `PEP 3110 "Catching Exceptions in Python 3000"
    <http://legacy.python.org/dev/peps/pep-3110/>`_
  * Removed syntax: ``a <> b``, ```a```, ``123l``, ``123L``, ``u'unicode'``,
    ``U'unicode'`` and ``def func(a, (b, c)): pass``
  * `PEP 3132 "Extended Iterable Unpacking" <https://www.python.org/dev/peps/pep-3132/>`_

* Python 2.6:

  * with: `PEP 343 "The "with" Statement"
    <http://legacy.python.org/dev/peps/pep-0343/>`_
  * ``b'bytes'`` syntax: `PEP 3112 "Bytes literals in Python 3000" <http://legacy.python.org/dev/peps/pep-3112/>`_

Old Python Versions
===================

* `Python 0.9.1 <https://www.python.org/download/releases/early/>`_
* `Python 1.5.2 <https://www.python.org/download/releases/1.5/>`_
* `Python 0.9.1 .. 2.0 source tarballs
  <https://www.python.org/ftp/python/src/>`_
* `David Beazley tests in 2017 (tweets)
  <https://twitter.com/dabeaz/status/934604333425004544>`_
* `neopythonic <http://neopythonic.blogspot.fr/>`_ by Guido van Rossum:
  Ramblings through technology, politics, culture and philosophy by the creator
  of the Python programming language.
* `History of Python (Wikipedia article)
  <https://en.wikipedia.org/wiki/History_of_Python>`_
* `The History of Python
  <http://python-history.blogspot.com/>`_ by Guido van Rossum:
  A series of articles on the history of the Python programming language and
  its community.

Python 3000
===========

* https://mail.python.org/pipermail/python-3000/
* https://www.python.org/dev/peps/pep-3000/
* https://www.python.org/dev/peps/pep-3100/