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This is Python version 3.15.0a6-rose-v2 alpha 6 (rose v2)
CPython build status on GitHub Actions
CPython build status on Azure DevOps
Copyright © 2001 Python Software Foundation. All rights reserved.
See the end of this file for further copyright and license information.
General Information
- Website: https://www.python.org
- Source code: https://github.com/python/cpython
- Issue tracker: https://github.com/python/cpython/issues
- 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.
Using Python
Installable Python kits, and information about using Python, are available at python.org.
Build Instructions
On Unix, Linux, BSD, macOS, and Cygwin:
./configure
make
make test
sudo make installThis 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 usable on all platforms. Refer to the 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.
On Windows, see PCbuild/readme.txt.
To build Windows installer, see Tools/msi/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 3.15 document. For a more detailed change log, read Misc/NEWS, but a full accounting of changes can only be gleaned from the commit history.
If you want to install multiple versions of Python, see the section below entitled "Installing multiple versions".
Documentation
Documentation for Python 3.15 is online, updated daily.
It can also be downloaded in many formats for faster access. The documentation is downloadable in HTML, EPUB, 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.
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 buildbottest.
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 and include relevant output from that command to show the issue.
See Running & Writing Tests 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/python3.X. 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 3.15 with
3.15 being the primary version, you would execute
make install in your 3.15 build directory and
make altinstall in the others.
Release Schedule
See PEP 790 for Python 3.15 release details.
Copyright and License Information
Copyright © 2001 Python Software Foundation. All rights reserved.
Copyright © 2000 BeOpen.com. All rights reserved.
Copyright © 1995-2001 Corporation for National Research Initiatives. All rights reserved.
Copyright © 1991-1995 Stichting Mathematisch Centrum. All rights reserved.
See the 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.