Repository files navigation

This action sets up a Python environment for use in actions by:

• optionally installing and adding to PATH a version of Python that is already installed in the tools cache.
• downloading, installing and adding to PATH an available version of Python from GitHub Releases (actions/python-versions) if a specific version is not available in the tools cache.
• failing if a specific version of Python is not preinstalled or available for download.
• optionally caching dependencies for pip and pipenv.
• registering problem matchers for error output.

• Ability to download, install and set up Python packages fromactions/python-versions that do not come preinstalled on runners.
  • Allows for pinning to a specific patch version of Python without the worry of it ever being removed or changed.
• Automatic setup and download of Python packages if using a self-hosted runner.
• Support for pre-release versions of Python.
• Support for installing any version of PyPy on-flight
• Support for built-in caching of pip and pipenv dependencies

Seeaction.yml

Basic:

steps:-uses:actions/checkout@v2-uses:actions/setup-python@v2with:python-version:'3.x'# Version range or exact version of a Python version to use, using SemVer's version range syntaxarchitecture:'x64'# optional x64 or x86. Defaults to x64 if not specified-run:python my_script.py

Matrix Testing:

jobs:build:runs-on:ubuntu-lateststrategy:matrix:python-version:[ '2.x', '3.x', 'pypy-2.7', 'pypy-3.6', 'pypy-3.7' ]name:Python ${{ matrix.python-version }} samplesteps:      -uses:actions/checkout@v2      -name:Set up Pythonuses:actions/setup-python@v2with:python-version:${{ matrix.python-version }}architecture:x64      -run:python my_script.py

Exclude a specific Python version:

jobs:build:runs-on:${{ matrix.os }}strategy:matrix:os:[ubuntu-latest, macos-latest, windows-latest]python-version:['2.7', '3.6', '3.7', '3.8', 'pypy-2.7', 'pypy-3.6']exclude:          -os:macos-latestpython-version:'3.8'          -os:windows-latestpython-version:'3.6'steps:      -uses:actions/checkout@v2      -name:Set up Pythonuses:actions/setup-python@v2with:python-version:${{ matrix.python-version }}      -name:Display Python versionrun:python -c "import sys; print(sys.version)"

Download and set up a version of Python that does not come preinstalled on an image:

jobs:build:runs-on:ubuntu-lateststrategy:matrix:# in this example, there is a newer version already installed, 3.7.7, so the older version will be downloadedpython-version:['3.5', '3.6', '3.7.4', '3.8']steps:    -uses:actions/checkout@v2    -uses:actions/setup-python@v2with:python-version:${{ matrix.python-version }}    -run:python my_script.py

Download and set up an accurate pre-release version of Python:

steps:-uses:actions/checkout@v2-uses:actions/setup-python@v2with:python-version:'3.9.0-beta.4'-run:python my_script.py

Download and set up the latest available version of Python (includes both pre-release and stable versions):

steps:-uses:actions/checkout@v2-uses:actions/setup-python@v2with:python-version:'3.9.0-alpha - 3.9.0'# SemVer's version range syntax-run:python my_script.py

Download and set up PyPy:

jobs:build:runs-on:ubuntu-lateststrategy:matrix:python-version:        -'pypy-3.6'# the latest available version of PyPy that supports Python 3.6        -'pypy-3.7'# the latest available version of PyPy that supports Python 3.7        -'pypy-3.7-v7.3.3'# Python 3.7 and PyPy 7.3.3steps:    -uses:actions/checkout@v2    -uses:actions/setup-python@v2with:python-version:${{ matrix.python-version }}    -run:python my_script.py

More details on PyPy syntax and examples of using preview / nightly versions of PyPy can be found in theAvailable versions of PyPy section.

Check out our detailed guide on usingPython with GitHub Actions.

setup-python is able to configure Python from two sources:

• Preinstalled versions of Python in the tools cache on GitHub-hosted runners.
  • For detailed information regarding the available versions of Python that are installed, seeSupported software.
  • For every minor version of Python, expect only the latest patch to be preinstalled.
  • If3.8.1 is installed for example, and3.8.2 is released, expect3.8.1 to be removed and replaced by3.8.2 in the tools cache.
  • If the exact patch version doesn't matter to you, specifying just the major and minor version will get you the latest preinstalled patch version. In the previous example, the version spec3.8 will use the3.8.2 Python version found in the cache.
• Downloadable Python versions from GitHub Releases (actions/python-versions).
  • All available versions are listed in theversion-manifest.json file.
  • If there is a specific version of Python that is not available, you can open an issue here

setup-python is able to configure PyPy from two sources:

• Preinstalled versions of PyPy in the tools cache on GitHub-hosted runners

  • For detailed information regarding the available versions of PyPy that are installed, seeSupported software.
  • For the latest PyPy release, all versions of Python are cached.
  • Cache is updated with a 1-2 week delay. If you specify the PyPy version aspypy-3.6, the cached version will be used although a newer version is available. If you need to start using the recently released version right after release, you should specify the exact PyPy version usingpypy-3.6-v7.3.3.

• Downloadable PyPy versions from theofficial PyPy site.

  • All available versions that we can download are listed inversions.json file.
  • PyPy < 7.3.3 are not available to install on-flight.
  • If some versions are not available, you can open an issue inhttps://foss.heptapod.net/pypy/pypy/

GitHub hosted runners have a tools cache that comes with a few versions of Python + PyPy already installed. This tools cache helps speed up runs and tool setup by not requiring any new downloads. There is an environment variable calledRUNNER_TOOL_CACHE on each runner that describes the location of this tools cache and there is where you will find Python and PyPy installed.setup-python works by taking a specific version of Python or PyPy in this tools cache and adding it to PATH.

GitHub virtual environments are setup inactions/virtual-environments. During the setup, the available versions of Python and PyPy are automatically downloaded, setup and documented.

• Tools cache setup for Ubuntu
• Tools cache setup for Windows

If there is a specific version of Python that you need and you don't want to worry about any potential breaking changes due to patch updates (going from3.7.5 to3.7.6 for example), you should specify the exact major, minor, and patch version (such as3.7.5)

• The only downside to this is that set up will take a little longer since the exact version will have to be downloaded if the exact version is not already installed on the runner due to more recent versions.
• MSI installers are used on Windows for this, so runs will take a little longer to set up vs Mac and Linux.

You should specify only a major and minor version if you are okay with the most recent patch version being used.

• There will be a single patch version already installed on each runner for every minor version of Python that is supported.
• The patch version that will be preinstalled, will generally be the latest and every time there is a new patch released, the older version that is preinstalled will be replaced.
• Using the most recent patch version will result in a very quick setup since no downloads will be required since a locally installed version Python on the runner will be used.

The version of PyPy should be specified in the formatpypy-<python_version>[-v<pypy_version>].The<pypy_version> parameter is optional and can be skipped. The latest version will be used in this case.

pypy-3.6 # the latest available version of PyPy that supports Python 3.6pypy-3.7 # the latest available version of PyPy that supports Python 3.7pypy-2.7 # the latest available version of PyPy that supports Python 2.7pypy-3.7-v7.3.3 # Python 3.7 and PyPy 7.3.3pypy-3.7-v7.x # Python 3.7 and the latest available PyPy 7.xpypy-3.7-v7.3.3rc1 # Python 3.7 and preview version of PyPypypy-3.7-nightly # Python 3.7 and nightly PyPy

The action has built-in functionality for caching and restoring dependencies. It usesactions/cache under the hood for caching dependencies but requires less configuration settings. Supported package managers arepip andpipenv. Thecache input is optional, and caching is turned off by default.

The action defaults to searching for a dependency file (requirements.txt for pip orPipfile.lock for pipenv) in the repository, and uses its hash as a part of the cache key. Usecache-dependency-path for cases where multiple dependency files are used, they are located in different subdirectories or different files for the hash want to be used.

• For pip, the action will cache global cache directory
• For pipenv, the action will cache virtualenv directory

Please 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 that can lead to an increase in total build time.

The requirements file format allows to specify dependency versions using logical operators (for example chardet>=3.0.4) or specify 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.

Caching pip dependencies:

steps:-uses:actions/checkout@v2-uses:actions/setup-python@v2with:python-version:'3.9'cache:'pip'-run:pip install -r requirements.txt-run:pip test

Caching pipenv dependencies:

steps:-uses:actions/checkout@v2-name:Install pipenvrun:pipx install pipenv-uses:actions/setup-python@v2with:python-version:'3.9'cache:'pipenv'-run:pipenv install-run:pipenv test

Using wildcard patterns to cache dependencies

steps:-uses:actions/checkout@v2-uses:actions/setup-python@v2with:python-version:'3.9'cache:'pip'cache-dependency-path:'**/requirements-dev.txt'-run:pip install -r subdirectory/requirements-dev.txt-run:pip test

Using a list of file paths to cache dependencies

steps:-uses:actions/checkout@v2-name:Install pipenvrun:pipx install pipenv-uses:actions/setup-python@v2with:python-version:'3.9'cache:'pipenv'cache-dependency-path:|      server/app/Pipfile.lock      __test__/app/Pipfile.lock-run:pipenv install-run:pipenv test

Python distributions are only available for the sameenvironments that GitHub Actions hosted environments are available for. If you are using an unsupported version of Ubuntu such as19.04 or another Linux distribution such as Fedora,setup-python will not work. If you have a supported self-hosted runner and you would like to usesetup-python, there are a few extra things you need to make sure are set up so that new versions of Python can be downloaded and configured on your runner.

If you are experiencing problems while configuring Python on your self-hosted runner, turn onstep debugging to see addition logs.

• Your runner needs to be running with administrator privileges so that the appropriate directories and files can be set up when downloading and installing a new version of Python for the first time.
• If your runner is configured as a service, make sure the account that is running the service has the appropriate write permissions so that Python can get installed. The defaultNT AUTHORITY\NETWORK SERVICE should be sufficient.
• You need7zip installed and added to yourPATH so that the downloaded versions of Python files can be extracted properly during first-time setup.
• MSI installers are used when setting up Python on Windows. A word of caution as MSI installers update registry settings.
• The 3.8 MSI installer for Windows will not let you install another 3.8 version of Python. Ifsetup-python fails for a 3.8 version of Python, make sure any previously installed versions are removed by going to "Apps & Features" in the Settings app.

• The Python packages that are downloaded fromactions/python-versions are originally compiled from source in/opt/hostedtoolcache/ with the--enable-shared flag, which makes them non-relocatable.
• Create an environment variable calledAGENT_TOOLSDIRECTORY and set it to/opt/hostedtoolcache. This controls where the runner downloads and installs tools.
  • In the same shell that your runner is using, typeexport AGENT_TOOLSDIRECTORY=/opt/hostedtoolcache.
  • A more permanent way of setting the environment variable is to create a.env file in the same directory as your runner and to addAGENT_TOOLSDIRECTORY=/opt/hostedtoolcache. This ensures the variable is always set if your runner is configured as a service.
• Create a directory calledhostedtoolcache inside/opt.
• The user starting the runner must have write permission to the/opt/hostedtoolcache directory. It is not possible to start the Linux runner withsudo and the/opt directory usually requires root privileges to write to. Check the current user and group that the runner belongs to by typingls -l inside the runners root directory.
• The runner can be granted write access to the/opt/hostedtoolcache directory using a few techniques:
  • The user starting the runner is the owner, and the owner has write permission.
  • The user starting the runner is in the owning group, and the owning group has write permission.
  • All users have write permission.
• One quick way to grant access is to change the user and group of/opt/hostedtoolcache to be the same as the runners usingchown.
  • sudo chown runner-user:runner-group opt/hostedtoolcache/.
• If your runner is configured as a service and you run into problems, make sure the user that the service is running as is correct. For more information, you cancheck the status of your self-hosted runner.

• The same setup that applies toLinux also applies toMac, just with a different tools cache directory.
• Create a directory called/Users/runner/hostedtoolcache.
• Set theAGENT_TOOLSDIRECTORY environment variable to/Users/runner/hostedtoolcache.
• Change the permissions of/Users/runner/hostedtoolcache so that the runner has write access.

setup-python helps keep your dependencies explicit and ensures consistent behavior between different runners. If you usepython in a shell on a GitHub hosted runner withoutsetup-python it will default to whatever is in PATH. The default version of Python in PATH vary between runners and can change unexpectedly so we recommend you always usesetup-python.

setup-python comes pre-installed on the appliance with GHES if Actions is enabled. When dynamically downloading Python distributions,setup-python downloads distributions fromactions/python-versions on github.com (outside of the appliance). These calls toactions/python-versions are made via unauthenticated requests, which are limited to60 requests per hour per IP. If more requests are made within the time frame, then you will start to see rate-limit errors during download that read##[error]API rate limit exceeded for....

To avoid hitting rate-limit problems, we recommendsetting up your own runner tool cache.

The scripts and documentation in this project are released under theMIT License.

Contributions are welcome! See ourContributor's Guide.