This action provides the following functionality for GitHub Actions users:
- Installing a version of Python or PyPy and (by default) adding it to the PATH
- Optionally caching dependencies for pip, pipenv and poetry
- Registering problem matchers for error output
steps: - uses: actions/checkout@v3 - uses: actions/setup-python@v4 with: python-version: '3.10' - run: python my_script.py
steps: - uses: actions/checkout@v3 - uses: actions/setup-python@v4 with: python-version: 'pypy3.9' - run: python my_script.py
python-version input is optional. If not supplied, the action will try to resolve the version from the default
.python-version file. If the
.python-version file doesn't exist Python or PyPy version from the PATH will be used. The default version of Python or PyPy in PATH varies between runners and can be changed unexpectedly so we recommend always setting Python version explicitly using the
The action will first check the local tool cache for a semver match. If unable to find a specific version in the tool cache, the action will attempt to download a version of Python from GitHub Releases and for PyPy from the official PyPy's dist.
For information regarding locally cached versions of Python or PyPy on GitHub hosted runners, check out GitHub Actions Runner Images.
Supported version syntax
python-version input supports the Semantic Versioning Specification and some special version notations (e.g.
x.y-dev syntax, etc.), for detailed examples please refer to the section: Using python-version input of the Advanced usage guide.
architecture input it is possible to specify the required Python or PyPy interpreter architecture:
x64. If the input is not specified the architecture defaults to
Caching packages dependencies
The action has built-in functionality for caching and restoring dependencies. It uses toolkit/cache under the hood for caching dependencies but requires less configuration settings. Supported package managers are
cache input is optional, and caching is turned off by default.
The action defaults to searching for a dependency file (
pyproject.toml for pip,
Pipfile.lock for pipenv or
poetry.lock for poetry) in the repository, and uses its hash as a part of the cache key. Input
cache-dependency-path is used for cases when multiple dependency files are used, they are located in different subdirectories or different files for the hash that want to be used.
pip, the action will cache the global cache directory
pipenv, the action will cache virtualenv directory
poetry, the action will cache virtualenv directories -- one for each poetry project found
Caching pip dependencies:
steps: - uses: actions/checkout@v3 - uses: actions/setup-python@v4 with: python-version: '3.9' cache: 'pip' # caching pip dependencies - run: pip install -r requirements.txt
Note: Restored cache will not be used if the requirements.txt file is not updated for a long time and a newer version of the dependency is available which can lead to an increase in total build time.
The requirements file format allows for specifying dependency versions using logical operators (for example chardet>=3.0.4) or specifying dependencies without any versions. In this case the pip install -r requirements.txt command will always try to install the latest available package version. To be sure that the cache will be used, please stick to a specific dependency version and update it manually if necessary.
See examples of using
poetry in the section: Caching packages of the Advanced usage guide.
- Using the python-version input
- Using the python-version-file input
- Check latest version
- Caching packages
- Outputs and environment variables
- Available versions of Python and PyPy
- Hosted tool cache
setup-pythonwith a self-hosted runner
- Allow pre-releases
The scripts and documentation in this project are released under the MIT License.
Contributions are welcome! See our Contributor's Guide.