index.rst

Python Developer's Guide

This guide is a comprehensive resource for :ref:`contributing <contributing>` to Python -- for both new and experienced contributors. It is :ref:`maintained <devguide>` by the same community that maintains Python. We welcome your contributions to Python!

Quick Reference

Here are the basic steps needed to get set up and contribute a patch. This is meant as a checklist, once you know the basics. For complete instructions please see the :ref:`setup guide <setup>`.

1. Install and set up :ref:`Git <vcsetup>` and other dependencies (see the :ref:`Git Setup <setup>` page for detailed information).

2. Fork the CPython repository to your GitHub account and :ref:`get the source code <checkout>` using:

   git clone https://github.com/<your_username>/cpython
   cd cpython

3. Build Python, on UNIX and macOS use:

   ./configure --with-pydebug && make -j

   and on Windows use:

   PCbuild\build.bat -e -d

   See also :ref:`more detailed instructions <compiling>`, :ref:`how to install and build dependencies <build-dependencies>`, and the platform-specific pages for :ref:`UNIX <unix-compiling>`, :ref:`macOS`, and :ref:`Windows <windows-compiling>`.

4. :ref:`Run the tests <runtests>`:

   ./python -m test -j3

   On :ref:`most <mac-python.exe>` macOS systems, replace :file:`./python` with :file:`./python.exe`. On Windows, use :file:`python.bat`.

5. Create a new branch where your work for the issue will go, e.g.:

   git checkout -b fix-issue-12345 main

   If an issue does not already exist, please create it. Trivial issues (e.g. typo fixes) do not require any issue to be created.

6. Once you fixed the issue, run the tests, run make patchcheck, and if everything is ok, commit.

7. Push the branch on your fork on GitHub and :ref:`create a pull request <pullrequest>`. Include the issue number using gh-NNNN in the pull request description. For example:

   gh-12345: Fix some bug in spam module

8. Add a News entry into the Misc/NEWS.d directory as individual file. The news entry can be created by using blurb-it, or the blurb tool and its blurb add command. Please read more about blurb in its repository.

Note

First time contributors will need to sign the Contributor Licensing Agreement (CLA) as described in the :ref:`Licensing <cla>` section of this guide.

Quick Links

Here are some links that you probably will reference frequently while contributing to Python:

• Issue tracker
• Buildbot status
• :ref:`help`
• PEPs (Python Enhancement Proposals)
• :ref:`gitbootcamp`

Contributing

We encourage everyone to contribute to Python and that's why we have put up this developer's guide. If you still have questions after reviewing the material in this guide, then the Core Python Mentorship group is available to help guide new contributors through the process.

A number of individuals from the Python community have contributed to a series of excellent guides at Open Source Guides.

Core developers and contributors alike will find the following guides useful:

• How to Contribute to Open Source
• Building Welcoming Communities

Guide for contributing to Python:

Contributors	Documentarians	Triagers	Core Developers
:ref:`setup`	:ref:`docquality`	:ref:`tracker`	:ref:`responsibilities`
:ref:`help`	:ref:`documenting`	:ref:`triaging`	:ref:`developers`
:ref:`pullrequest`	:ref:`style-guide`	:ref:`helptriage`	:ref:`committing`
:ref:`runtests`	:ref:`rst-primer`	:ref:`experts`	:ref:`devcycle`
:ref:`fixingissues`	:ref:`translating`	:ref:`labels`	:ref:`motivations`
:ref:`communication`		:ref:`gh-faq`	:ref:`office hour`
:ref:`gitbootcamp`		:ref:`triage-team`	:ref:`experts`
:ref:`devcycle`

We recommend that the documents in this guide be read as needed. You can stop where you feel comfortable and begin contributing immediately without reading and understanding these documents all at once. If you do choose to skip around within the documentation, be aware that it is written assuming preceding documentation has been read so you may find it necessary to backtrack to fill in missing concepts and terminology.

Proposing changes to Python itself

Improving Python's code, documentation and tests are ongoing tasks that are never going to be "finished", as Python operates as part of an ever-evolving system of technology. An even more challenging ongoing task than these necessary maintenance activities is finding ways to make Python, in the form of the standard library and the language definition, an even better tool in a developer's toolkit.

While these kinds of change are much rarer than those described above, they do happen and that process is also described as part of this guide:

• :ref:`stdlibchanges`
• :ref:`langchanges`

Other Interpreter Implementations

This guide is specifically for contributing to the Python reference interpreter, also known as CPython (while most of the standard library is written in Python, the interpreter core is written in C and integrates most easily with the C and C++ ecosystems).

There are other Python implementations, each with a different focus. Like CPython, they always have more things they would like to do than they have developers to work on them. Some major examples that may be of interest are:

• PyPy: A Python interpreter focused on high speed (JIT-compiled) operation on major platforms
• Jython: A Python interpreter focused on good integration with the Java Virtual Machine (JVM) environment
• IronPython: A Python interpreter focused on good integration with the Common Language Runtime (CLR) provided by .NET and Mono
• Stackless: A Python interpreter focused on providing lightweight microthreads while remaining largely compatible with CPython specific extension modules
• MicroPython: A tiny Python interpreter with small subset of the Python standard library that is optimised to run on microcontrollers and in constrained environments.
• CircuitPython: A fork of MicroPython designed to simplify experimenting and learning to code on low-cost microcontroller boards.

Key Resources

• Coding style guides

  • PEP 7 (Style Guide for C Code)
  • PEP 8 (Style Guide for Python Code)

• Issue tracker

  • :ref:`experts`

• Buildbot status

• Source code

  • Browse online
  • Snapshot of the *main* branch

• PEPs (Python Enhancement Proposals)
• :ref:`help`
• :ref:`developers`

Additional Resources

• Anyone can clone the sources for this guide. See :ref:`devguide`.

• Help with ...

  • :ref:`exploring`
  • :ref:`grammar`
  • :ref:`parser`
  • :ref:`compiler`
  • :ref:`garbage_collector`

• Tool support

  • :ref:`gdb`
  • :ref:`clang`
  • Various tools with configuration files as found in the Misc directory
  • Information about editors and their configurations can be found in the wiki

• python.org maintenance
• :ref:`Search this guide <search>`

Code of Conduct

Please note that all interactions on Python Software Foundation-supported infrastructure is covered by the PSF Code of Conduct, which includes all infrastructure used in the development of Python itself (e.g. mailing lists, issue trackers, GitHub, etc.). In general this means everyone is expected to be open, considerate, and respectful of others no matter what their position is within the project.

Status of Python branches

Moved to :ref:`versions`

Full Table of Contents

.. toctree::
   :maxdepth: 3

   getting-started/index
   developer-workflow/index
   triage/index
   documentation/index
   testing/index
   development-tools/index
   core-developers/index
   internals/index
   versions