Python Tests workflow (prosysscience/JSSEnv)

The Python Tests workflow from prosysscience/JSSEnv, explained and optimized by Latchkey.

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Source: prosysscience/JSSEnv.github/workflows/python-tests.ymlLicense MITView source

What it does

This is the Python Tests workflow from the prosysscience/JSSEnv repository, a real project running GitHub Actions. It is shown here with attribution under its MIT license.

Below, Latchkey shows a faster, safer version produced by its optimization engine.

The workflow

workflow (.yml)

name: Python Tests

on:
  push:
    branches: [ master, main ]
  pull_request:
    branches: [ master, main ]

jobs:
  test:
    runs-on: ubuntu-latest
    strategy:
      fail-fast: false
      matrix:
        python-version: ['3.8', '3.9', '3.10', '3.11', '3.12']

    steps:
    - uses: actions/checkout@v4
    
    - name: Set up Python ${{ matrix.python-version }}
      uses: actions/setup-python@v5
      with:
        python-version: ${{ matrix.python-version }}
        
    - name: Install dependencies
      run: |
        # Upgrade pip and core tools
        python -m pip install --upgrade pip setuptools wheel
        
        # Install gymnasium explicitly first
        python -m pip install gymnasium==0.29.1
        
        # Install numpy and pandas (version depends on Python version)
        if [[ "${{ matrix.python-version }}" == "3.8" ]]; then
          python -m pip install "numpy>=1.20.0,<1.24.0" "pandas>=1.3.0,<2.0.0"
        elif [[ "${{ matrix.python-version }}" == "3.9" || "${{ matrix.python-version }}" == "3.10" ]]; then
          python -m pip install "numpy>=1.20.0,<2.0.0" "pandas>=1.3.0,<2.1.0"
        else
          python -m pip install "numpy>=1.24.0" "pandas>=2.0.0"
        fi
        
        # Install other core dependencies
        python -m pip install plotly imageio psutil requests kaleido
        
        # Install development dependencies
        python -m pip install pytest pytest-cov flake8 codecov
        
        # Finally install the package in development mode
        python -m pip install -e .
        
        # List installed packages for debugging
        python -m pip list
        
    - name: Lint with flake8
      run: |
        # stop the build if there are Python syntax errors or undefined names
        flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics || true
        # exit-zero treats all errors as warnings
        flake8 . --count --exit-zero --max-line-length=120 --statistics
        
    - name: Test with pytest and coverage
      run: |
        pytest -v --cov=JSSEnv tests/
        
    - name: Upload coverage to Codecov
      uses: codecov/codecov-action@v4
      with:
        fail_ci_if_error: false

  build-package:
    needs: test
    runs-on: ubuntu-latest
    
    steps:
    - uses: actions/checkout@v4
    
    - name: Set up Python 3.10
      uses: actions/setup-python@v5
      with:
        python-version: '3.10'
        
    - name: Install dependencies
      run: |
        python -m pip install --upgrade pip setuptools wheel
        python -m pip install build
        
    - name: Build package
      run: |
        python -m build
        
    - name: Store build artifacts
      uses: actions/upload-artifact@v4
      with:
        name: dist
        path: dist/

The same workflow, on Latchkey

Estimated ~20% faster on cache hits, plus fewer wasted runs and a safer supply chain. Added and changed lines are highlighted.

name: Python Tests
 
on:
  push:
    branches: [ master, main ]
  pull_request:
    branches: [ master, main ]
 
concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true
 
jobs:
  test:
    timeout-minutes: 30
    runs-on: latchkey-small
    strategy:
      fail-fast: false
      matrix:
        python-version: ['3.8', '3.9', '3.10', '3.11', '3.12']
 
    steps:
    - uses: actions/checkout@v4
    
    - name: Set up Python ${{ matrix.python-version }}
      uses: actions/setup-python@v5
      with:
        cache: 'pip'
        python-version: ${{ matrix.python-version }}
        
    - name: Install dependencies
      run: |
        # Upgrade pip and core tools
        python -m pip install --upgrade pip setuptools wheel
        
        # Install gymnasium explicitly first
        python -m pip install gymnasium==0.29.1
        
        # Install numpy and pandas (version depends on Python version)
        if [[ "${{ matrix.python-version }}" == "3.8" ]]; then
          python -m pip install "numpy>=1.20.0,<1.24.0" "pandas>=1.3.0,<2.0.0"
        elif [[ "${{ matrix.python-version }}" == "3.9" || "${{ matrix.python-version }}" == "3.10" ]]; then
          python -m pip install "numpy>=1.20.0,<2.0.0" "pandas>=1.3.0,<2.1.0"
        else
          python -m pip install "numpy>=1.24.0" "pandas>=2.0.0"
        fi
        
        # Install other core dependencies
        python -m pip install plotly imageio psutil requests kaleido
        
        # Install development dependencies
        python -m pip install pytest pytest-cov flake8 codecov
        
        # Finally install the package in development mode
        python -m pip install -e .
        
        # List installed packages for debugging
        python -m pip list
        
    - name: Lint with flake8
      run: |
        # stop the build if there are Python syntax errors or undefined names
        flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics || true
        # exit-zero treats all errors as warnings
        flake8 . --count --exit-zero --max-line-length=120 --statistics
        
    - name: Test with pytest and coverage
      run: |
        pytest -v --cov=JSSEnv tests/
        
    - name: Upload coverage to Codecov
      uses: codecov/codecov-action@v4
      with:
        fail_ci_if_error: false
 
  build-package:
    timeout-minutes: 30
    needs: test
    runs-on: latchkey-small
    
    steps:
    - uses: actions/checkout@v4
    
    - name: Set up Python 3.10
      uses: actions/setup-python@v5
      with:
        cache: 'pip'
        python-version: '3.10'
        
    - name: Install dependencies
      run: |
        python -m pip install --upgrade pip setuptools wheel
        python -m pip install build
        
    - name: Build package
      run: |
        python -m build
        
    - name: Store build artifacts
      uses: actions/upload-artifact@v4
      with:
        name: dist
        path: dist/

What changed

Run on Latchkey managed runners with one line (runs-on), which apply the fixes below automatically and self-heal transient failures. This example uses latchkey-small; pick the runner size that fits the job.
Cancel superseded runs when a branch or PR gets a newer push.
Cache dependency installs on the setup step so they are served from cache.
Add a job timeout so a hung step cannot burn hours of runner time.

1 third-party action is referenced by a movable tag. Pin it to the commit SHA (Latchkey resolves and applies this automatically) so a repointed tag cannot change what runs.

What Latchkey heals here

This workflow has steps that commonly fail on transient issues (network, registries, flaky browsers). On Latchkey managed runners they are detected, retried, and self-healed instead of failing your build:

Dependency installs

This workflow runs 2 jobs (6 with the matrix expanded) per trigger. On Latchkey the same minutes cost up to 58% less than GitHub-hosted, with zero queue time.

Actions used in this workflow

actions/checkout actions/setup-python codecov/codecov-action actions/upload-artifact