add cache

.github/workflows/build-test.yaml

@@ -2,7 +2,7 @@ name: Python package
 
 on:
   pull_request:
-    types: [opened, synchronize, reopened]
+    types: [opened, synchronize, reopened, edited, ready_for_review]
   push:
     branches: [master]
 
@@ -12,20 +12,33 @@ jobs:
 
     steps:
       - uses: actions/checkout@v4
+
       - name: Set up Python
         uses: actions/setup-python@v5
         with:
           python-version: "3.9"
           cache: "pip"
+
+      # this caches the entire python installation, including all packages, so that we don't have to reinstall them every time
+      # we run this action. This is a huge time saver.
+      - uses: actions/cache@v2
+        with:
+          path: ${{ env.pythonLocation }}
+          key: ${{ env.pythonLocation }}-${{ hashFiles('setup.py') }}-${{ hashFiles('requirements.txt') }}
+
       - name: Install Python Dependencies
         run: |
           python -m pip install --upgrade pip
           pip install -r requirements.txt -e .[dev]
+
       - name: Lint with pylint
         run: pylint --disable=C0115,C0116,C0104,C0114,W0511 src tests
+
       - name: Check with flake8
         run: flake8
+
       - name: Check import sorting
         run: isort --check-only -p savage -p tests .
+
       - name: Check black formatting
         run: black --check --exclude=$(VENV_DIR) --line-length=100 .