Add module docstrings #437

	# Run some code checks with GitHub Actions.

	name: Code checks

	on:
	push:
	branches:
	- "main"
	pull_request:

	permissions:
	contents: read
	# Allow 1Password/check-signed-commits-action to leave comments on
	# pull requests.
	pull-requests: write

	jobs:

	checks:
	runs-on: ubuntu-latest
	steps:
	- name: Check out sources
	uses: actions/checkout@v3
	with:
	fetch-depth: 0 # since we need to diff against origin/main.

	# https://github.com/marketplace/actions/check-signed-commits-in-pr
	- name: Check that commits are signed
	uses: 1Password/check-signed-commits-action@v1

	- name: Set up Python 3.9
	uses: actions/setup-python@v4
	with:
	python-version: "3.9"
	cache: 'pip' # cache pip dependencies
	cache-dependency-path: pyproject.toml

	- name: Install dependencies
	run: \|
	python -m pip install --upgrade pip
	python -m pip install black==23.* isort==5.*

	- name: Run "black --check"
	run: \|
	python -m black --check .

	- name: Run "isort --check"
	run: \|
	python -m isort --profile black --check .

	# Remind PR authors to update CHANGELOG.md
	- name: Check that Changelog has been updated
	if: github.event_name == 'pull_request' && !contains(github.event.pull_request.labels.*.name, 'no changelog')
	run: \|
	# `git diff --exit-code` exits with 1 if there were
	# differences and 0 means no differences. Here we negate
	# that, because we want to fail if changelog has not been
	# updated.
	! git diff --exit-code "origin/${GITHUB_BASE_REF}" -- CHANGELOG.md

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