README.rst - platform/external/python/cpython3 - Gitiles

 This is Python version 3.10.1
 =============================

 .. image:: https://travis-ci.com/python/cpython.svg?branch=master
    :alt: CPython build status on Travis CI
    :target: https://travis-ci.com/python/cpython

 .. image:: https://github.com/python/cpython/workflows/Tests/badge.svg
    :alt: CPython build status on GitHub Actions
    :target: https://github.com/python/cpython/actions

 .. image:: https://dev.azure.com/python/cpython/_apis/build/status/Azure%20Pipelines%20CI?branchName=master
    :alt: CPython build status on Azure DevOps
    :target: https://dev.azure.com/python/cpython/_build/latest?definitionId=4&branchName=master

 .. image:: https://img.shields.io/badge/discourse-join_chat-brightgreen.svg
    :alt: Python Discourse chat
    :target: https://discuss.python.org/


 Copyright (c) 2001-2021 Python Software Foundation.  All rights reserved.

 See the end of this file for further copyright and license information.

 .. contents::

 General Information
 -------------------

 - Website: https://www.python.org
 - Source code: https://github.com/python/cpython
 - Issue tracker: https://bugs.python.org
 - Documentation: https://docs.python.org
 - Developer's Guide: https://devguide.python.org/

 Contributing to CPython
 -----------------------

 For more complete instructions on contributing to CPython development,
 see the `Developer Guide`_.

 .. _Developer Guide: https://devguide.python.org/

 Using Python
 ------------

 Installable Python kits, and information about using Python, are available at
 `python.org`_.

 .. _python.org: https://www.python.org/

 Build Instructions
 ------------------

 On Unix, Linux, BSD, macOS, and Cygwin::

     ./configure
     make
     make test
     sudo make install

 This will install Python as ``python3``.

 You can pass many options to the configure script; run ``./configure --help``
 to find out more.  On macOS case-insensitive file systems and on Cygwin,
 the executable is called ``python.exe``; elsewhere it's just ``python``.

 Building a complete Python installation requires the use of various
 additional third-party libraries, depending on your build platform and
 configure options.  Not all standard library modules are buildable or
 useable on all platforms.  Refer to the
 `Install dependencies <https://devguide.python.org/setup/#install-dependencies>`_
 section of the `Developer Guide`_ for current detailed information on
 dependencies for various Linux distributions and macOS.

 On macOS, there are additional configure and build options related
 to macOS framework and universal builds.  Refer to `Mac/README.rst
 <https://github.com/python/cpython/blob/master/Mac/README.rst>`_.

 On Windows, see `PCbuild/readme.txt
 <https://github.com/python/cpython/blob/master/PCbuild/readme.txt>`_.

 If you wish, you can create a subdirectory and invoke configure from there.
 For example::

     mkdir debug
     cd debug
     ../configure --with-pydebug
     make
     make test

 (This will fail if you *also* built at the top-level directory.  You should do
 a ``make clean`` at the top-level first.)

 To get an optimized build of Python, ``configure --enable-optimizations``
 before you run ``make``.  This sets the default make targets up to enable
 Profile Guided Optimization (PGO) and may be used to auto-enable Link Time
 Optimization (LTO) on some platforms.  For more details, see the sections
 below.

 Profile Guided Optimization
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^

 PGO takes advantage of recent versions of the GCC or Clang compilers.  If used,
 either via ``configure --enable-optimizations`` or by manually running
 ``make profile-opt`` regardless of configure flags, the optimized build
 process will perform the following steps:

 The entire Python directory is cleaned of temporary files that may have
 resulted from a previous compilation.

 An instrumented version of the interpreter is built, using suitable compiler
 flags for each flavor. Note that this is just an intermediary step.  The
 binary resulting from this step is not good for real-life workloads as it has
 profiling instructions embedded inside.

 After the instrumented interpreter is built, the Makefile will run a training
 workload.  This is necessary in order to profile the interpreter's execution.
 Note also that any output, both stdout and stderr, that may appear at this step
 is suppressed.

 The final step is to build the actual interpreter, using the information
 collected from the instrumented one.  The end result will be a Python binary
 that is optimized; suitable for distribution or production installation.


 Link Time Optimization
 ^^^^^^^^^^^^^^^^^^^^^^

 Enabled via configure's ``--with-lto`` flag.  LTO takes advantage of the
 ability of recent compiler toolchains to optimize across the otherwise
 arbitrary ``.o`` file boundary when building final executables or shared
 libraries for additional performance gains.


 What's New
 ----------

 We have a comprehensive overview of the changes in the `What's New in Python
 3.10 <https://docs.python.org/3.10/whatsnew/3.10.html>`_ document.  For a more
 detailed change log, read `Misc/NEWS
 <https://github.com/python/cpython/blob/master/Misc/NEWS.d>`_, but a full
 accounting of changes can only be gleaned from the `commit history
 <https://github.com/python/cpython/commits/master>`_.

 If you want to install multiple versions of Python, see the section below
 entitled "Installing multiple versions".


 Documentation
 -------------

 `Documentation for Python 3.10 <https://docs.python.org/3.10/>`_ is online,
 updated daily.

 It can also be downloaded in many formats for faster access.  The documentation
 is downloadable in HTML, PDF, and reStructuredText formats; the latter version
 is primarily for documentation authors, translators, and people with special
 formatting requirements.

 For information about building Python's documentation, refer to `Doc/README.rst
 <https://github.com/python/cpython/blob/master/Doc/README.rst>`_.


 Converting From Python 2.x to 3.x
 ---------------------------------

 Significant backward incompatible changes were made for the release of Python
 3.0, which may cause programs written for Python 2 to fail when run with Python
 3.  For more information about porting your code from Python 2 to Python 3, see
 the `Porting HOWTO <https://docs.python.org/3/howto/pyporting.html>`_.


 Testing
 -------

 To test the interpreter, type ``make test`` in the top-level directory.  The
 test set produces some output.  You can generally ignore the messages about
 skipped tests due to optional features which can't be imported.  If a message
 is printed about a failed test or a traceback or core dump is produced,
 something is wrong.

 By default, tests are prevented from overusing resources like disk space and
 memory.  To enable these tests, run ``make testall``.

 If any tests fail, you can re-run the failing test(s) in verbose mode.  For
 example, if ``test_os`` and ``test_gdb`` failed, you can run::

     make test TESTOPTS="-v test_os test_gdb"

 If the failure persists and appears to be a problem with Python rather than
 your environment, you can `file a bug report <https://bugs.python.org>`_ and
 include relevant output from that command to show the issue.

 See `Running & Writing Tests <https://devguide.python.org/runtests/>`_
 for more on running tests.

 Installing multiple versions
 ----------------------------

 On Unix and Mac systems if you intend to install multiple versions of Python
 using the same installation prefix (``--prefix`` argument to the configure
 script) you must take care that your primary python executable is not
 overwritten by the installation of a different version.  All files and
 directories installed using ``make altinstall`` contain the major and minor
 version and can thus live side-by-side.  ``make install`` also creates
 ``${prefix}/bin/python3`` which refers to ``${prefix}/bin/pythonX.Y``.  If you
 intend to install multiple versions using the same prefix you must decide which
 version (if any) is your "primary" version.  Install that version using ``make
 install``.  Install all other versions using ``make altinstall``.

 For example, if you want to install Python 2.7, 3.6, and 3.10 with 3.10 being the
 primary version, you would execute ``make install`` in your 3.10 build directory
 and ``make altinstall`` in the others.


 Issue Tracker and Mailing List
 ------------------------------

 Bug reports are welcome!  You can use the `issue tracker
 <https://bugs.python.org>`_ to report bugs, and/or submit pull requests `on
 GitHub <https://github.com/python/cpython>`_.

 You can also follow development discussion on the `python-dev mailing list
 <https://mail.python.org/mailman/listinfo/python-dev/>`_.


 Proposals for enhancement
 -------------------------

 If you have a proposal to change Python, you may want to send an email to the
 `comp.lang.python`_ or `python-ideas`_ mailing lists for initial feedback.  A
 Python Enhancement Proposal (PEP) may be submitted if your idea gains ground.
 All current PEPs, as well as guidelines for submitting a new PEP, are listed at
 `python.org/dev/peps/ <https://www.python.org/dev/peps/>`_.

 .. _python-ideas: https://mail.python.org/mailman/listinfo/python-ideas/
 .. _comp.lang.python: https://mail.python.org/mailman/listinfo/python-list


 Release Schedule
 ----------------

 See :pep:`619` for Python 3.10 release details.


 Copyright and License Information
 ---------------------------------

 Copyright (c) 2001-2021 Python Software Foundation.  All rights reserved.

 Copyright (c) 2000 BeOpen.com.  All rights reserved.

 Copyright (c) 1995-2001 Corporation for National Research Initiatives.  All
 rights reserved.

 Copyright (c) 1991-1995 Stichting Mathematisch Centrum.  All rights reserved.

 See the `LICENSE <https://github.com/python/cpython/blob/master/LICENSE>`_ for
 information on the history of this software, terms & conditions for usage, and a
 DISCLAIMER OF ALL WARRANTIES.

 This Python distribution contains *no* GNU General Public License (GPL) code,
 so it may be used in proprietary projects.  There are interfaces to some GNU
 code but these are entirely optional.

 All trademarks referenced herein are property of their respective holders.
	This is Python version 3.10.1
	=============================

	.. image:: https://travis-ci.com/python/cpython.svg?branch=master
	:alt: CPython build status on Travis CI
	:target: https://travis-ci.com/python/cpython

	.. image:: https://github.com/python/cpython/workflows/Tests/badge.svg
	:alt: CPython build status on GitHub Actions
	:target: https://github.com/python/cpython/actions

	.. image:: https://dev.azure.com/python/cpython/_apis/build/status/Azure%20Pipelines%20CI?branchName=master
	:alt: CPython build status on Azure DevOps
	:target: https://dev.azure.com/python/cpython/_build/latest?definitionId=4&branchName=master

	.. image:: https://img.shields.io/badge/discourse-join_chat-brightgreen.svg
	:alt: Python Discourse chat
	:target: https://discuss.python.org/


	Copyright (c) 2001-2021 Python Software Foundation. All rights reserved.

	See the end of this file for further copyright and license information.

	.. contents::

	General Information
	-------------------

	- Website: https://www.python.org
	- Source code: https://github.com/python/cpython
	- Issue tracker: https://bugs.python.org
	- Documentation: https://docs.python.org
	- Developer's Guide: https://devguide.python.org/

	Contributing to CPython
	-----------------------

	For more complete instructions on contributing to CPython development,
	see the `Developer Guide`_.

	.. _Developer Guide: https://devguide.python.org/

	Using Python
	------------

	Installable Python kits, and information about using Python, are available at
	`python.org`_.

	.. _python.org: https://www.python.org/

	Build Instructions
	------------------

	On Unix, Linux, BSD, macOS, and Cygwin::

	./configure
	make
	make test
	sudo make install

	This will install Python as ``python3``.

	You can pass many options to the configure script; run ``./configure --help``
	to find out more. On macOS case-insensitive file systems and on Cygwin,
	the executable is called ``python.exe``; elsewhere it's just ``python``.

	Building a complete Python installation requires the use of various
	additional third-party libraries, depending on your build platform and
	configure options. Not all standard library modules are buildable or
	useable on all platforms. Refer to the
	`Install dependencies <https://devguide.python.org/setup/#install-dependencies>`_
	section of the `Developer Guide`_ for current detailed information on
	dependencies for various Linux distributions and macOS.

	On macOS, there are additional configure and build options related
	to macOS framework and universal builds. Refer to `Mac/README.rst
	<https://github.com/python/cpython/blob/master/Mac/README.rst>`_.

	On Windows, see `PCbuild/readme.txt
	<https://github.com/python/cpython/blob/master/PCbuild/readme.txt>`_.

	If you wish, you can create a subdirectory and invoke configure from there.
	For example::

	mkdir debug
	cd debug
	../configure --with-pydebug
	make
	make test

	(This will fail if you also built at the top-level directory. You should do
	a ``make clean`` at the top-level first.)

	To get an optimized build of Python, ``configure --enable-optimizations``
	before you run ``make``. This sets the default make targets up to enable
	Profile Guided Optimization (PGO) and may be used to auto-enable Link Time
	Optimization (LTO) on some platforms. For more details, see the sections
	below.

	Profile Guided Optimization
	^^^^^^^^^^^^^^^^^^^^^^^^^^^

	PGO takes advantage of recent versions of the GCC or Clang compilers. If used,
	either via ``configure --enable-optimizations`` or by manually running
	``make profile-opt`` regardless of configure flags, the optimized build
	process will perform the following steps:

	The entire Python directory is cleaned of temporary files that may have
	resulted from a previous compilation.

	An instrumented version of the interpreter is built, using suitable compiler
	flags for each flavor. Note that this is just an intermediary step. The
	binary resulting from this step is not good for real-life workloads as it has
	profiling instructions embedded inside.

	After the instrumented interpreter is built, the Makefile will run a training
	workload. This is necessary in order to profile the interpreter's execution.
	Note also that any output, both stdout and stderr, that may appear at this step
	is suppressed.

	The final step is to build the actual interpreter, using the information
	collected from the instrumented one. The end result will be a Python binary
	that is optimized; suitable for distribution or production installation.


	Link Time Optimization
	^^^^^^^^^^^^^^^^^^^^^^

	Enabled via configure's ``--with-lto`` flag. LTO takes advantage of the
	ability of recent compiler toolchains to optimize across the otherwise
	arbitrary ``.o`` file boundary when building final executables or shared
	libraries for additional performance gains.


	What's New
	----------

	We have a comprehensive overview of the changes in the `What's New in Python
	3.10 <https://docs.python.org/3.10/whatsnew/3.10.html>`_ document. For a more
	detailed change log, read `Misc/NEWS
	<https://github.com/python/cpython/blob/master/Misc/NEWS.d>`_, but a full
	accounting of changes can only be gleaned from the `commit history
	<https://github.com/python/cpython/commits/master>`_.

	If you want to install multiple versions of Python, see the section below
	entitled "Installing multiple versions".


	Documentation
	-------------

	`Documentation for Python 3.10 <https://docs.python.org/3.10/>`_ is online,
	updated daily.

	It can also be downloaded in many formats for faster access. The documentation
	is downloadable in HTML, PDF, and reStructuredText formats; the latter version
	is primarily for documentation authors, translators, and people with special
	formatting requirements.

	For information about building Python's documentation, refer to `Doc/README.rst
	<https://github.com/python/cpython/blob/master/Doc/README.rst>`_.


	Converting From Python 2.x to 3.x
	---------------------------------

	Significant backward incompatible changes were made for the release of Python
	3.0, which may cause programs written for Python 2 to fail when run with Python
	3. For more information about porting your code from Python 2 to Python 3, see
	the `Porting HOWTO <https://docs.python.org/3/howto/pyporting.html>`_.


	Testing
	-------

	To test the interpreter, type ``make test`` in the top-level directory. The
	test set produces some output. You can generally ignore the messages about
	skipped tests due to optional features which can't be imported. If a message
	is printed about a failed test or a traceback or core dump is produced,
	something is wrong.

	By default, tests are prevented from overusing resources like disk space and
	memory. To enable these tests, run ``make testall``.

	If any tests fail, you can re-run the failing test(s) in verbose mode. For
	example, if ``test_os`` and ``test_gdb`` failed, you can run::

	make test TESTOPTS="-v test_os test_gdb"

	If the failure persists and appears to be a problem with Python rather than
	your environment, you can `file a bug report <https://bugs.python.org>`_ and
	include relevant output from that command to show the issue.

	See `Running & Writing Tests <https://devguide.python.org/runtests/>`_
	for more on running tests.

	Installing multiple versions
	----------------------------

	On Unix and Mac systems if you intend to install multiple versions of Python
	using the same installation prefix (``--prefix`` argument to the configure
	script) you must take care that your primary python executable is not
	overwritten by the installation of a different version. All files and
	directories installed using ``make altinstall`` contain the major and minor
	version and can thus live side-by-side. ``make install`` also creates
	``${prefix}/bin/python3`` which refers to ``${prefix}/bin/pythonX.Y``. If you
	intend to install multiple versions using the same prefix you must decide which
	version (if any) is your "primary" version. Install that version using ``make
	install``. Install all other versions using ``make altinstall``.

	For example, if you want to install Python 2.7, 3.6, and 3.10 with 3.10 being the
	primary version, you would execute ``make install`` in your 3.10 build directory
	and ``make altinstall`` in the others.


	Issue Tracker and Mailing List
	------------------------------

	Bug reports are welcome! You can use the `issue tracker
	<https://bugs.python.org>`_ to report bugs, and/or submit pull requests `on
	GitHub <https://github.com/python/cpython>`_.

	You can also follow development discussion on the `python-dev mailing list
	<https://mail.python.org/mailman/listinfo/python-dev/>`_.


	Proposals for enhancement
	-------------------------

	If you have a proposal to change Python, you may want to send an email to the
	`comp.lang.python`_ or `python-ideas`_ mailing lists for initial feedback. A
	Python Enhancement Proposal (PEP) may be submitted if your idea gains ground.
	All current PEPs, as well as guidelines for submitting a new PEP, are listed at
	`python.org/dev/peps/ <https://www.python.org/dev/peps/>`_.

	.. _python-ideas: https://mail.python.org/mailman/listinfo/python-ideas/
	.. _comp.lang.python: https://mail.python.org/mailman/listinfo/python-list


	Release Schedule
	----------------

	See :pep:`619` for Python 3.10 release details.


	Copyright and License Information
	---------------------------------

	Copyright (c) 2001-2021 Python Software Foundation. All rights reserved.

	Copyright (c) 2000 BeOpen.com. All rights reserved.

	Copyright (c) 1995-2001 Corporation for National Research Initiatives. All
	rights reserved.

	Copyright (c) 1991-1995 Stichting Mathematisch Centrum. All rights reserved.

	See the `LICENSE <https://github.com/python/cpython/blob/master/LICENSE>`_ for
	information on the history of this software, terms & conditions for usage, and a
	DISCLAIMER OF ALL WARRANTIES.

	This Python distribution contains no GNU General Public License (GPL) code,
	so it may be used in proprietary projects. There are interfaces to some GNU
	code but these are entirely optional.

	All trademarks referenced herein are property of their respective holders.