CI: codestyle and coverage checks

.flake8

@@ -0,0 +1,9 @@
+[flake8]
+max-line-length = 100
+# E123: closing bracket does not match indentation of opening bracket's line
+# E126: continuation line over-indented for hanging indent
+# E226: missing whitespace around arithmetic operator
+# E402: Module level import not at top of file
+# W503: line break before binary operator
+# W504: line break after binary operator
+ignore = E123,E126,E226,E402,W503,W504

.github/workflows/on_pr.yml

@@ -5,6 +5,19 @@ on:
   pull_request:
 
 jobs:
+  flake8-lint:
+    runs-on: ubuntu-latest
+    name: Code Style
+    steps:
+      - name: Check out source repository
+        uses: actions/checkout@v3
+      - name: Set up Python environment
+        uses: actions/setup-python@v4
+        with:
+          python-version: "3.11"
+      - name: flake8 codestyle
+        uses: py-actions/flake8@v2
+
   build:
     runs-on: ${{ matrix.os }}
     strategy: