actions/setup-python caching for setup.py projects

I used to use a combination of actions/setup-python and actions/cache in all of my Python GitHub Actions projects in order to install Python dependencies via a cache, rather than hitting PyPI to download copies every time.

actions/setup-python added built-in caching a while ago, but it wasn't obvious to me from the documentation how I could use that with setup.py based projects (as opposed to projects that install dependencies via Pipfile or requirements.txt).

The trick is to use cache: pip and cache-dependency-path: setup.py as arguments to the actions/setup-python action.

Here's the pattern I found that works:

    - name: Set up Python 3.11
      uses: actions/setup-python@v4
      with:
        python-version: '3.11'
        cache: pip
        cache-dependency-path: setup.py
    - name: Install dependencies
      run: |
        pip install '.[test]'

And here's a full .github/workflows/test.yml configuration that uses a matrix to run tests against five currently supported Python versions:

name: Test

on: [push, pull_request]

permissions:
  contents: read

jobs:
  test:
    runs-on: ubuntu-latest
    strategy:
      matrix:
        python-version: ["3.7", "3.8", "3.9", "3.10", "3.11"]
    steps:
    - uses: actions/checkout@v3
    - name: Set up Python ${{ matrix.python-version }}
      uses: actions/setup-python@v4
      with:
        python-version: ${{ matrix.python-version }}
        cache: pip
        cache-dependency-path: setup.py
    - name: Install dependencies
      run: |
        pip install '.[test]'
    - name: Run tests
      run: |
        pytest

I updated my various cookiecutter templates to use this new pattern in this issue.

Created 2022-11-28T14:26:50-08:00, updated 2022-11-28T22:06:53-08:00 · History · Edit