Python in GitHub actions

• actions/setup-python
• mamba-org/setup-micromamba

Pip packages

The actions/setup-python actions installs python with a specific version and could cache downloaded Python packages. (But not the installed environment).

uv is a drop-in replacement for pip, an extremely fast Python package and project manager written in Rust. uv caches the environment by default.

name: UV example

env:
  UV_SYSTEM_PYTHON: 1

jobs:
  python:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - name: Set up Python
        uses: actions/setup-python@v5
        with:
          python-version: '3.x'
          check-latest: true
      - name: Install the latest version of uv
        uses: astral-sh/setup-uv@v5
        with:
          version: "latest"
      - name: Install requirements
        run: uv pip install -r requirements.txt

Conda packages

The mamba-org/setup-micromamba action installs the micromamba package manager and conda package dependencies. It also caches the Python runtime environment.

- uses: mamba-org/setup-micromamba@v1
  with:
    environment-file: environment.yml
    init-shell: bash
    cache-environment: true
    post-cleanup: 'all'

- name: Run custom command in micromamba environment
  shell: micromamba-shell {0}
  run: python --version