GitHub Actions: Lint and test our Python code

.github/workflows/Python_tests.yml

@@ -0,0 +1,35 @@
+name: Python_tests
+on: [push, pull_request]
+jobs:
+  Python_tests:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [macos-latest]
+        python-version: [2.7, 3.8]
+    steps:
+      - uses: actions/checkout@v1
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v1
+        with:
+          python-version: ${{ matrix.python-version }}
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install flake8 pytest -r requirements.txt
+      #- name: Check formatting with black
+      #  if: matrix.python-version == '3.8'
+      #  run: |
+      #     pip install black
+      #     black --check .
+      - name: Lint with flake8
+        run: |
+          # stop the build if there are Python syntax errors or undefined names
+          flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics
+          # exit-zero treats all errors as warnings. The GitHub editor is 127 chars wide
+          flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
+      #- name: Test with pytest
+      #  run: pytest
+      #- name: Run doctests with pytest
+      #  run: pytest --doctest-modules