CI: Add PyPI deployment to GHA worfklow

Author: effigies

.github/workflows/pythonpackage.yml

@@ -6,6 +6,9 @@
 # Packages that use it probably do not want to continue testing with editable installations,
 # quadrupling their test load.
 
+# For deployment, it will be necessary to create a PyPI API token and store it as a secret
+# https://docs.github.com/en/actions/reference/encrypted-secrets
+
 name: Python package
 
 # Set once
@@ -15,11 +18,12 @@ env:
 on:
   push:
     branches: [ main ]
+    tags: [ '*' ]
   pull_request:
     branches: [ main ]
 
 jobs:
-  build:
+  test:
     runs-on: ubuntu-latest
     strategy:
       matrix:
@@ -50,3 +54,35 @@ jobs:
     - name: Test with pytest
       run: |
         pytest -sv --doctest-modules pydra/tasks/$SUBPACKAGE
+
+  deploy:
+    needs: test
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: [3.9]
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        submodules: recursive
+        fetch-depth: 0
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v2
+      with:
+        python-version: ${{ matrix.python-version }}
+    - name: Install build tools
+      run: python -m pip install --upgrade pip setuptools wheel twine
+    - name: Build source and wheel distributions
+      run: python setup.py sdist bdist_wheel
+    - name: Check distributions
+      run: twine check dist/*
+    - uses: actions/upload-artifact@v2
+      with:
+        name: distributions
+        path: dist/
+    - name: Upload to PyPI (on tags)
+      if: github.event_name == 'push' && startsWith(github.ref, 'refs/tags')
+      uses: pypa/gh-action-pypi-publish@master
+      with:
+        user: __token__
+        password: ${{ secrets.PYPI_API_TOKEN }}