=============== Getting Started =============== We’re pleased that you are interested in working on pip. This document is meant to get you setup to work on pip and to act as a guide and reference to the development setup. If you face any issues during this process, please `open an issue`_ about it on the issue tracker. Get the source code =================== To work on pip, you first need to get the source code of pip. The source code is available on `GitHub`_. .. code-block:: console $ git clone https://github.com/pypa/pip $ cd pip Development Environment ======================= pip is a command line application written in Python. For developing pip, you should `install Python`_ on your computer. For developing pip, you need to install :pypi:`nox`. The full development setup would then be: .. tab:: Unix/macOS .. code-block:: shell python -m venv .venv source .venv/bin/activate python -m pip install nox .. tab:: Windows .. code-block:: shell py -m venv .venv .venv\Scripts\activate py -m pip install nox Running pip From Source Tree ============================ To run the pip executable from your source tree during development, install pip locally using editable installation (inside a virtualenv). You can then invoke your local source tree pip normally (be sure virtualenv is active). .. tab:: Unix/macOS .. code-block:: shell python -m pip install -e . python -m pip --version .. tab:: Windows .. code-block:: shell py -m pip install -e . py -m pip --version Running Tests ============= pip's tests are written using the :pypi:`pytest` test framework and :mod:`unittest.mock`. :pypi:`nox` is used to automate the setup and execution of pip's tests. It is preferable to run the tests in parallel for a better experience during development, since the tests can take a long time to finish when run sequentially. To run tests: .. code-block:: console $ nox -s test-3.10 -- -n auto To run tests without parallelization, run: .. code-block:: console $ nox -s test-3.10 The example above runs tests against Python 3.10. You can also use other versions like ``3.9`` and ``pypy3``. ``nox`` has been configured to forward any additional arguments it is given to ``pytest``. This enables the use of pytest's `rich CLI`_. As an example, you can select tests using the various ways that pytest provides: .. code-block:: console $ # Using file name $ nox -s test-3.10 -- tests/functional/test_install.py $ # Using markers $ nox -s test-3.10 -- -m unit $ # Using keywords $ nox -s test-3.10 -- -k "install and not wheel" .. note:: When running pip's tests with OS distribution Python versions, be aware that some functional tests may fail due to potential patches introduced by the distribution. For all tests to pass consider: - Installing Python from `python.org`_ or compile from source - Or, using `pyenv`_ to assist with source compilation Running pip's entire test suite requires supported version control tools (subversion, bazaar, git, and mercurial) to be installed. If you are missing any of these VCS, those tests should be skipped automatically. You can also explicitly tell pytest to skip those tests: .. code-block:: console $ nox -s test-3.10 -- -k "not svn" $ nox -s test-3.10 -- -k "not (svn or git)" .. _python.org: https://www.python.org/downloads/ .. _pyenv: https://github.com/pyenv/pyenv Running Linters =============== pip uses :pypi:`pre-commit` for managing linting of the codebase. ``pre-commit`` performs various checks on all files in pip and uses tools that help follow a consistent code style within the codebase. To use linters locally, run: .. code-block:: console $ nox -s lint .. note:: Avoid using ``# noqa`` comments to suppress linter warnings - wherever possible, warnings should be fixed instead. ``# noqa`` comments are reserved for rare cases where the recommended style causes severe readability problems. Running pip under a debugger ============================ In order to debug pip's behavior, you can run it under a debugger like so: .. code-block:: console $ python -m pdb -m pip --debug ... Replace the ``...`` with arguments you'd like to run pip with. Give PDB the ``c`` ("continue") command afterwards, to run the process. The ``--debug`` flag disables pip's exception handler, which would normally catch all unhandled exceptions. With this flag, pip will let these exceptions propagate outside of its main subroutine, letting them get caught by the debugger. This way you'll be able to debug an exception post-mortem via PDB. Building Documentation ====================== pip's documentation is built using :pypi:`Sphinx`. The documentation is written in reStructuredText. To build it locally, run: .. code-block:: console $ nox -s docs The built documentation can be found in the ``docs/build`` folder. For each Pull Request made the documentation is deployed following this link: .. code-block:: none https://pip--<PR-NUMBER>.org.readthedocs.build/en/<PR-NUMBER> What Next? ========== The following pages may be helpful for new contributors on where to look next in order to start contributing. * Some `good first issues`_ on GitHub for new contributors * A deep dive into `pip's architecture`_ * A guide on `triaging issues`_ for issue tracker * Getting started with Git - `Hello World for Git`_ - `Understanding the GitHub flow`_ - `Start using Git on the command line`_ .. _`open an issue`: https://github.com/pypa/pip/issues/new?title=Trouble+with+pip+development+environment .. _`install Python`: https://realpython.com/installing-python/ .. _`PEP 484 type-comments`: https://www.python.org/dev/peps/pep-0484/#suggested-syntax-for-python-2-7-and-straddling-code .. _`rich CLI`: https://docs.pytest.org/en/latest/usage.html#specifying-tests-selecting-tests .. _`GitHub`: https://github.com/pypa/pip .. _`good first issues`: https://github.com/pypa/pip/labels/good%20first%20issue .. _`pip's architecture`: https://pip.pypa.io/en/latest/development/architecture/ .. _`triaging issues`: https://pip.pypa.io/en/latest/development/issue-triage/ .. _`Hello World for Git`: https://guides.github.com/activities/hello-world/ .. _`Understanding the GitHub flow`: https://guides.github.com/introduction/flow/ .. _`Start using Git on the command line`: https://docs.gitlab.com/ee/gitlab-basics/start-using-git.html