Add CI workflow to lint and check formatting of Python files

On every push and pull request that affects relevant files, and periodically, run flake8 to check the Python files of
the repository for issues and black to check formatting.

The .flake8 file is used to configure flake8:
https://flake8.pycqa.org/en/latest/user/configuration.html

Author: per1234

.flake8

@@ -0,0 +1,12 @@
+# Source: https://github.com/arduino/tooling-project-assets/blob/main/workflow-templates/assets/check-python/.flake8
+# See: https://flake8.pycqa.org/en/latest/user/configuration.html
+# The code style defined in this file is the official standardized style to be used in all Arduino tooling projects and
+# should not be modified.
+
+[flake8]
+doctests = True
+# W503 and W504 are mutually exclusive. PEP 8 recommends line break before.
+ignore = W503
+max-complexity = 10
+max-line-length = 120
+select = E,W,F,C,N

.github/workflows/check-python-task.yml

@@ -0,0 +1,79 @@
+# Source: https://github.com/arduino/tooling-project-assets/blob/main/workflow-templates/check-python-task.md
+name: Check Python
+
+# See: https://docs.github.com/en/actions/reference/events-that-trigger-workflows
+on:
+  push:
+    paths:
+      - ".github/workflows/check-python-task.ya?ml"
+      - "**/.flake8"
+      - "**/poetry.lock"
+      - "**/pyproject.toml"
+      - "**/setup.cfg"
+      - "Taskfile.ya?ml"
+      - "**/tox.ini"
+      - "**.py"
+  pull_request:
+    paths:
+      - ".github/workflows/check-python-task.ya?ml"
+      - "**/.flake8"
+      - "**/poetry.lock"
+      - "**/pyproject.toml"
+      - "**/setup.cfg"
+      - "Taskfile.ya?ml"
+      - "**/tox.ini"
+      - "**.py"
+  workflow_dispatch:
+  repository_dispatch:
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v2
+
+      - name: Install Python
+        uses: actions/setup-python@v2
+        with:
+          python-version: "3.9"
+
+      - name: Install Poetry
+        run: pip install poetry
+
+      - name: Install Task
+        uses: arduino/setup-task@v1
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+          version: 3.x
+
+      - name: Run flake8
+        run: task python:lint
+
+  formatting:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v2
+
+      - name: Install Python
+        uses: actions/setup-python@v2
+        with:
+          python-version: "3.9"
+
+      - name: Install Poetry
+        run: pip install poetry
+
+      - name: Install Task
+        uses: arduino/setup-task@v1
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+          version: 3.x
+
+      - name: Format Python code
+        run: task python:format
+
+      - name: Check formatting
+        run: git diff --color --exit-code

README.md

@@ -13,6 +13,7 @@
 [![Sync Labels status](https://github.com/arduino/tooling-project-assets/actions/workflows/sync-labels.yml/badge.svg)](https://github.com/arduino/tooling-project-assets/actions/workflows/sync-labels.yml)
 [![Check Workflows status](https://github.com/arduino/tooling-project-assets/actions/workflows/check-workflows-task.yml/badge.svg)](https://github.com/arduino/tooling-project-assets/actions/workflows/check-workflows-task.yml)
 [![Spell Check status](https://github.com/arduino/tooling-project-assets/actions/workflows/spell-check-task.yml/badge.svg)](https:/github.com/arduino/tooling-project-assets/actions/workflows/spell-check-task.yml)
+[![Check Python status](https://github.com/arduino/tooling-project-assets/actions/workflows/check-python-task.yml/badge.svg)](https://github.com/arduino/tooling-project-assets/actions/workflows/check-python-task.yml)
 
 The [Arduino](https://www.arduino.cc/) Tooling Team's collection of reusable project infrastructure assets.
 

Taskfile.yml

@@ -214,6 +214,22 @@ tasks:
     cmds:
       - poetry update
 
+  # Source: https://github.com/arduino/tooling-project-assets/blob/main/workflow-templates/assets/check-python-task/Taskfile.yml
+  python:lint:
+    desc: Lint Python code
+    deps:
+      - task: poetry:install-deps
+    cmds:
+      - poetry run flake8 --show-source
+
+  # Source: https://github.com/arduino/tooling-project-assets/blob/main/workflow-templates/assets/check-python-task/Taskfile.yml
+  python:format:
+    desc: Format Python files
+    deps:
+      - task: poetry:install-deps
+    cmds:
+      - poetry run black .
+
   # Source: https://github.com/arduino/tooling-project-assets/blob/main/workflow-templates/assets/check-yaml-task/Taskfile.yml
   yaml:lint:
     desc: Check for problems with YAML files