updated README.md and requirements_dev.txt #2

	name: MyPy static code checking

	on:
	push:
	branches:
	- master
	- github-actions
	pull_request:
	branches:
	- master

	jobs:
	run-tests:
	strategy:
	fail-fast: false
	matrix:
	os: [ubuntu-latest, macos-latest, windows-latest]
	python-version:
	- "3.7"
	- "3.8"
	- "3.9"
	- "3.10"
	- "3.11"
	- "3.12"
	name: MyPy on
	runs-on: ${{ matrix.os }}

	steps:
	- name: Checkout code
	uses: actions/checkout@v4

	- name: Setting up Python
	uses: actions/setup-python@v5
	with:
	python-version: ${{ matrix.python-version }}

	- name: Installing dependencies
	run: python -m pip install mypy pytest .

	# - name: Running MyPy static type checking on src and tests
	# run: \|
	# mypy calculator
	# mypy tests

	- name: Running MyPy static type checking on src
	run: mypy calculator

	- name: Running MyPy static type checking on tests
	run: mypy tests

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