Use python3

.github/workflows/test-windows.yml

@@ -43,8 +43,8 @@ jobs:
     - name: Print build system information
       run: python .github/workflows/system-info.py
 
-    - name: python -m pip install wheel pytest pytest-cov pytest-timeout defusedxml
+    - name: python3 -m pip install wheel pytest pytest-cov pytest-timeout defusedxml
-      run: python -m pip install wheel pytest pytest-cov pytest-timeout defusedxml
+      run: python3 -m pip install wheel pytest pytest-cov pytest-timeout defusedxml
 
     - name: Install dependencies
       id: install

winbuild/build.rst

@@ -91,7 +91,7 @@ Some binary dependencies (e.g. ``fribidi.dll``) will be stored in the
 ``winbuild\build\bin`` directory; this directory should be added to ``PATH``
 before running tests.
 
-Build and install Pillow, then run ``python -m pytest Tests``
+Build and install Pillow, then run ``python3 -m pytest Tests``
 from the root Pillow directory.
 
 Example