refactor<>: add the formatting to work only on the pushed files and n…

…ot the whole repository

.github/workflows/python-CI.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [3.8, 3.9, 3.10]
+        python-version: [3.8, 3.9]
 
     steps:
       - uses: actions/checkout@v2
@@ -23,6 +23,12 @@ jobs:
         run: |
           python -m pip install --upgrade pip
           pip install black
-      - name: Check code formatting with Black
+      - name: Check code formatting with Black on changed files
         run: |
-          black --check .
+          FILES=$(git diff --name-only ${{ github.event.before }} ${{ github.sha }} | grep '\.py$' | xargs)
+          if [ ! -z "$FILES" ]; then
+            # Check the formatting of those files with black
+            black --check $FILES
+          else
+            echo "No Python files have changed."
+          fi