Python package workflow (lovasoa/marshmallow_dataclass)
The Python package workflow from lovasoa/marshmallow_dataclass, explained and optimized by Latchkey.
CI health: D - needs work
Run this on Latchkey for self-healing, caching, and up to 58% lower cost.
Grade your own workflow free or run it on Latchkey →What it does
This is the Python package workflow from the lovasoa/marshmallow_dataclass 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
# This workflow will install Python dependencies and run tests with a variety of Python versions
# For more information see: https://help.github.com/actions/language-and-framework-guides/using-python-with-github-actions
name: Python package
on: [push, pull_request]
jobs:
build:
strategy:
fail-fast: false
matrix:
os: ["ubuntu-latest"]
python_version: ["3.9", "3.10", "3.11", "3.12", "3.13", "3.14", "pypy3.10"]
runs-on: ${{ matrix.os }}
steps:
- uses: actions/checkout@v4
- name: Set up Python ${{ matrix.python-version }}
uses: actions/setup-python@v5
with:
python-version: ${{ matrix.python_version }}
- name: set pip cache
uses: actions/cache@v4
with:
path: |
~/.cache/pip
key: ${{ matrix.python_version }}-${{ hashFiles('setup.py') }}
- name: Use latest pip
run: python -m pip install --upgrade pip
- name: Pre-install PyYAML without --pre
if: ${{ startsWith(matrix.python_version, 'pypy') }}
# Temporary workaround:
# PyYAML fails to build with Cython 3.0.0a
# see https://github.com/yaml/pyyaml/issues/601
run: pip install PyYAML
- name: Install dependencies
run: pip install --pre -e '.[docs,tests]'
- name: Test with pytest
run: pytest -ra
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.
# This workflow will install Python dependencies and run tests with a variety of Python versions # For more information see: https://help.github.com/actions/language-and-framework-guides/using-python-with-github-actions name: Python package on: [push, pull_request] concurrency: group: ${{ github.workflow }}-${{ github.ref }} cancel-in-progress: true jobs: build: timeout-minutes: 30 strategy: fail-fast: false matrix: os: ["ubuntu-latest"] python_version: ["3.9", "3.10", "3.11", "3.12", "3.13", "3.14", "pypy3.10"] runs-on: ${{ matrix.os }} 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: set pip cache uses: actions/cache@v4 with: path: | ~/.cache/pip key: ${{ matrix.python_version }}-${{ hashFiles('setup.py') }} - name: Use latest pip run: python -m pip install --upgrade pip - name: Pre-install PyYAML without --pre if: ${{ startsWith(matrix.python_version, 'pypy') }} # Temporary workaround: # PyYAML fails to build with Cython 3.0.0a # see https://github.com/yaml/pyyaml/issues/601 run: pip install PyYAML - name: Install dependencies run: pip install --pre -e '.[docs,tests]' - name: Test with pytest run: pytest -ra
What changed
- 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.
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 1 job (7 with the matrix expanded) per trigger. On Latchkey the same minutes cost up to 58% less than GitHub-hosted, with zero queue time.