GitHub Actions

Overview

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.github/workflows

Creating a basic workflow

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.github/workflows/basic.yml

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name: Basic GitHub Actions Workflow

on:
  push:
  pull_request:
  workflow_dispatch:

jobs:
  basic-job:
    runs-on: ubuntu-latest

    steps:
      - name: Run a one-line script
        run: echo "Hello, world!"

1. The name field gives your workflow a name. This name will be displayed in the Actions tab of your GitHub repository.

2. The on field specifies when your workflow should run. In this case, it's configured to run on push events, pull_request events, and workflow_dispatch events.

3. The jobs field describes the jobs that make up your workflow. This workflow includes a single job called basic-job.

4. The runs-on field inside the basic-job job specifies the type of machine to run the job on. Here it is set to run on the latest available version of Ubuntu.

5. The steps field is a list of tasks to perform in the job. Each item in the list is a separate task. Here, we have one task that runs a basic shell command (echo "Hello, world!"). The name field gives the step a name that will be displayed in the GitHub Actions UI.

6. The run field specifies the command to run. Here, it's just echoing "Hello, world!" to the console.

Creating a Python-specific workflow

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Python package
By GitHub Actions

Create and test a Python package on multiple Python versions.

1. change the name to "Python versions", and the filename to python_versions.yml

2. add the workflow_dispatch trigger, just like in the basic file

3. Change the "Install dependencies" step to run the following block:

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           python -m pip install --upgrade pip setuptools wheel
           python -m pip install .[dev]

4. Change the "Lint with flake8" step to just run flake8 (with no options at all)

1. Checkout Code: The first step uses an action, actions/checkout@v3, which checks out your repository's code onto the runner, so the job can access it.

2. Set Up Python: The next step uses another action, actions/setup-python@v3, to set up a Python environment with the version specified in the matrix.

3. Install Dependencies: The third step runs a series of shell commands to install Python dependencies. It first updates pip, setuptools, and wheel, then installs the development dependencies for the project using pip install .[dev]. If you are unfamiliar with this, look in the repository's setup.py, which lists the project dependencies near the bottom.

4. Lint with flake8: The fourth step runs the flake8 linter to check the code for styling errors. flake8 is a tool for enforcing Python's PEP 8 style guide, and it can find many different types of common problems with your code. You can check the flake8 configuration for this project in the .flake8 file in the repository.

5. Test with pytest: The last step runs the pytest command to execute tests. pytest is a Python testing framework.

Identify and fix the errors

Create a workflow on multiple operating systems

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# This workflow will install Python dependencies, run tests and lint with a variety of Python versions
# For more information see: https://docs.github.com/en/actions/automating-builds-and-tests/building-and-testing-python

name: Operating systems

on:
  push:
    branches: ["main"]
  pull_request:
    branches: ["main"]
  workflow_dispatch:

jobs:
  build:
    runs-on: ${{ matrix.os }}
    strategy:
      fail-fast: false
      matrix:
        os: [ubuntu-latest, macos-latest, windows-latest]

    steps:
      - uses: actions/checkout@v3
      - name: Set up Python 3.10
        uses: actions/setup-python@v3
        with:
          python-version: "3.10"
      - name: Install dependencies
        run: |
          python -m pip install --upgrade pip setuptools wheel
          python -m pip install .[dev]
      - name: Lint with flake8
        run: |
          flake8
      - name: Test with pytest
        run: |
          pytest

Next steps

1. [optional] read more about GitHub's hosted runners.

2. [optional] read more about the syntax for GitHub Actions.