reduce python dev requirement to 3.9

.github/workflows/python-app.yml

@@ -5,35 +5,43 @@ name: Python application
 
 on:
   push:
-    branches: [ "main" ]
+    branches: ["main"]
   pull_request:
-    branches: [ "main" ]
+    branches: ["main"]
 
 permissions:
   contents: read
 
 jobs:
   build:
-
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v3
-    - name: Set up Python 3.10
-      uses: actions/setup-python@v3
-      with:
-        python-version: "3.10"
-    - name: Install dependencies
-      run: |
-        python -m pip install --upgrade pip
-        pip install flake8 pytest
-        if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
-    - 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
+      - uses: actions/checkout@v3
+      - name: Set up Python 3.9
+        uses: actions/setup-python@v3
+        with:
+          python-version: "3.9"
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install poetry
+          poetry export -f requirements.txt --with dev >> requirements.txt
+          pip install -r requirements.txt
+      - name: Lint with flake8
+        run: |
+          python -m pip install --upgrade pip
+          pip install poetry
+          poetry export -f requirements.txt --with dev >> requirements.txt
+          pip install -r requirements.txt
+          # stop the build if there are Python syntax errors or undefined names
+          flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics -config ./tox.ini
+          # 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 -config ./tox.ini
+      - name: Test with pytest
+        run: |
+          python -m pip install --upgrade pip
+          pip install poetry
+          poetry export -f requirements.txt --with dev >> requirements.txt
+          pip install -r requirements.txt
+          pytest