Cache Python packages with virtual environments

continuous-integration.yml

# .github/workflows/continuous-integration.yml
---

name: Continuous Integration
on:
  push:
  schedule:
    - cron: "0 */4 * * *" # At minute 0 past every 4th hour
jobs:
  static_analysis_python:
    name: Static analysis for Python codes
    runs-on: ubuntu-latest
    steps:
      - name: Check out
        uses: actions/checkout@v1
        with:
          fetch-depth: 1
      - name: Set up Python
        uses: actions/setup-python@v1
        with:
          python-version: 3.7
      - name: Cache Python packages
        uses: actions/cache@preview
        with:
          path: .venv
          key: ${{ runner.os }}-pip-${{ hashFiles('**/requirements.txt') }}
          restore-keys: |
            ${{ runner.os }}-pip-
      - name: Install dependencies
        run: |
          python -m venv .venv
          source .venv/bin/activate
          python -m pip install -r requirements.txt
      - name: Run static analysis tools
        run: |
          source .venv/bin/activate
          flake8 --verbose --jobs=auto