Several small fixes and improvements #9

	name: build

	on: [push, pull_request]

	jobs:
	build:

	runs-on: ubuntu-latest
	strategy:
	matrix:
	python-version: ["3.8", "3.9", "3.10", "3.11"]

	steps:
	- uses: actions/checkout@v3
	- name: Set up Python ${{ matrix.python-version }}
	uses: actions/setup-python@v4
	with:
	python-version: ${{ matrix.python-version }}
	- name: Cache pip
	uses: actions/cache@v3
	with:
	path: ~/.cache/pip
	key: ${{ runner.os }}-pip-${{ hashFiles('**/requirements.txt') }}
	restore-keys: \|
	${{ runner.os }}-pip-
	- name: Install dependencies
	run: \|
	python -m pip install --upgrade pip
	pip install ruff pytest pytest-cov
	if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
	- name: Install package
	run: \|
	pip install .
	- name: Lint with ruff
	run: \|
	# stop the build if there are Python syntax errors or undefined names
	ruff --format=github --select=E9,F63,F7,F82 --target-version=py37 .
	# default set of ruff rules with GitHub Annotations
	ruff --format=github --target-version=py37 .
	- name: Test with pytest
	run: \|
	pytest --cov=./ --cov-report=xml
	- name: Upload coverage to Codecov
	uses: codecov/codecov-action@v3
	with:
	token: ${{ secrets.CODECOV_TOKEN }}

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