Use astral-sh/setup-uv in the setup-python composite action

.github/actions/setup-python/action.yml

@@ -6,12 +6,6 @@ inputs:
   python-version:
     description: "Python version (e.g. '3.7', '3.8.13', '3.11.0-alpha.1', '3.x')."
     required: true
-  install-seed-packages:
-    description: >
-      Set to 'true' to install and/or upgrade seed packages (pip, setuptools, and wheel)
-      before installing other packages.
-    required: false
-    default: "false"
   requirements:
     description: "Optional list of arguments passed to `uv pip install` (e.g. 'numpy==1.19.5', '-r requirements.txt')."
     required: false
@@ -23,37 +17,19 @@ runs:
       with:
         python-version: "${{ inputs.python-version }}"
 
+    # Install uv and enable its built-in cache. The cache key takes the
+    # platform, the uv version, and a hash of the files below into account.
+    # See https://docs.astral.sh/uv/guides/integration/github/ for details.
+    # NOTE: setup-uv publishes immutable releases only (no
+    #       floating major tags), so we pin the full version
     - name: Install uv
-      shell: bash
-      run: pip install --upgrade uv
-
-    # >>>>>>>> Caching uv packages >>>>>>>>
-
-    - name: Get uv cache dir
-      id: uv-cache
-      shell: bash
-      run: echo "dir=$(uv cache dir)" >> $GITHUB_OUTPUT
-
-    - name: Get the current date in format YYYYWW (year and week-of-year)
-      id: get-date
-      shell: bash
-      run: echo "date=$(/bin/date -u "+%Y%U")" >> $GITHUB_OUTPUT
-
-    - name: uv cache
-      uses: actions/cache@v4
+      uses: astral-sh/setup-uv@v9.0.0
       with:
-        path: ${{ steps.uv-cache.outputs.dir }}
-        # The cache's TTL is 7 days (one week)
-        key: uv-${{ runner.os }}-${{ inputs.python-version }}-${{ steps.get-date.outputs.date }}
-        # Fall back to the previous week's cache
-        restore-keys: uv-${{ runner.os }}-${{ inputs.python-version }}-
-
-    # <<<<<<<< Caching uv packages <<<<<<<<
-
-    - name: Install and/or upgrade seed packages
-      if: ${{ inputs.install-seed-packages == 'true' }}
-      shell: bash
-      run: uv pip install --verbose --system --upgrade pip setuptools wheel
+        enable-cache: true
+        cache-suffix: "py${{ inputs.python-version }}"
+        cache-dependency-glob: |
+          pyproject.toml
+          requirements/*.txt
 
     - name: Install requirements
       if: ${{ inputs.requirements != '' }}

docs/reference/changelog.md

@@ -16,6 +16,7 @@ Unreleased changes
 - Bump codecov/codecov-action from 5 to 6 ({gh-pr}`371`)
 - Bump actions/github-script from 8 to 9 ({gh-pr}`373`)
 - pre-commit autoupdate ({gh-pr}`374`)
+- Use the official `astral-sh/setup-uv` action to install and cache `uv` in CI ({gh-pr}`386`)
 
 ---