Add a ruff.toml config file for linting python and add ruff to the li…

…nting workflow file.

.github/workflows/linting.yml

@@ -39,6 +39,7 @@ jobs:
           . ftorch/bin/activate
           pip install torch torchvision --index-url https://download.pytorch.org/whl/cpu
           pip install fortitude-lint
+          pip install ruff
 
       # Run CMake build to get compile commands for clang
       - name: FTorch CMake
@@ -54,7 +55,7 @@ jobs:
 
       # Apply Fortran linter, fortitude
       # Configurable using the fortitude.toml file if present
-      - name: Fortitude Source
+      - name: fortitude source
         if: always()
         run: |
           cd ${{ github.workspace }}
@@ -63,7 +64,7 @@ jobs:
 
       # Apply C++ and C linter and formatter, clang
       # Configurable using the .clang-format and .clang-tidy config files if present
-      - name: Clang Source
+      - name: clang source
         if: always()
         uses: cpp-linter/cpp-linter-action@v2
         id: linter
@@ -81,9 +82,17 @@ jobs:
         run: exit 1
 
       # Apply Fortran linter, fortitude to examples
-      - name: Fortitude Examples
+      - name: fortitude examples
         if: always()
         run: |
           cd ${{ github.workspace }}
           . ftorch/bin/activate
           fortitude check examples
+
+      - name: ruff
+        if: always()
+        run: |
+          cd ${{ github.workspace }}
+          . ftorch/bin/activate
+          ruff format --diff ./
+          ruff check --diff ./

ruff.toml

@@ -0,0 +1,24 @@
+[format]
+docstring-code-format = true
+
+[lint]
+# See https://docs.astral.sh/ruff/rules for full details of each ruleset.
+
+# Enable:  D: `pydocstyle`, PL: `pylint`, I: `isort`, W: `pycodestyle whitespace`
+#          NPY: `numpy`, FLY: `flynt`, RUF: `ruff`
+#          From flake8: "ARG", "SLF", "S", "BLE", "B", "A", "C4", "EM", "ICN",
+#                       "PIE", "Q", "RSE", "SIM", "TID"
+select = ["D", "PL", "I", "E", "W", "NPY", "FLY", "RUF",
+          "ARG", "SLF", "S", "BLE","B", "A", "C4", "EM", "ICN", "PIE", "Q", "RSE",
+          "SIM", "TID"]
+
+# Enable D417 (Missing argument description) on top of the NumPy convention.
+extend-select = ["D417"]
+
+# Ignore SIM108 (use ternary instead of if-else) as it can arguably obscure intent.
+# Ignore RUF002 (ambiguous characters) as it does not allow apostrophes in strings.
+ignore = ["SIM108", "RUF002"]
+
+[lint.pydocstyle]
+# Use NumPy convention for checking docstrings
+convention = "numpy"