Python linting (#528)

Co-authored-by: Alexander Lanin <[email protected]>
Co-authored-by: Maximilian Sören Pollak <[email protected]>

Author: MaximilianSoerenPollak

.devcontainer/devcontainer.json

@@ -10,7 +10,8 @@
 				"usernamehw.errorlens",
 				"hediet.vscode-drawio",
 				"swyddfa.esbonio",
-				"lextudio.restructuredtext"
+				"lextudio.restructuredtext",
+				"charliermarsh.ruff"
 			]
 		}
 	}

.vscode/extensions.json

@@ -11,5 +11,8 @@
 
         // ErrorLens highlights errors and warnings in your code / docs
         "usernamehw.errorlens",
+
+        // Linting and formatting for Python (LSP via ruff server)
+        "charliermarsh.ruff",
     ]
 }

.vscode/settings.json

@@ -34,6 +34,12 @@
         "editor.rulers": [
             79
         ],
+        // Opinionated option for the future:
+        // "editor.formatOnSave": true,
+        "editor.codeActionsOnSave": {
+            "source.sortImports": "explicit"
+        },
+        "editor.defaultFormatter": "charliermarsh.ruff",
     },
 
     // Markdown Settings

pyproject.toml

@@ -0,0 +1,37 @@
+# This file is at the root level, as it applies to all Python code,
+# not only to docs or to tools.
+
+[tool.pyright]
+typeCheckingMode = "standard"
+pythonVersion = "3.12" # Keep in sync with MODULE.bazel
+
+exclude = [
+    "**/__pycache__",
+    "**/.*",
+    "bazel-*",
+]
+
+[tool.ruff]
+target-version = "py312"
+extend-exclude = [
+    "__pycache__",
+    ".*",
+    "bazel-*",
+]
+
+# Selected rules for clean code, readability, and bug prevention
+lint.select = [
+    "E",    # pycodestyle (PEP8)
+    "F",    # pyflakes (undefined vars, unused imports)
+    "I",    # isort (import sorting)
+    "B",    # flake8-bugbear (likely bugs)
+    "C90",  # mccabe (complexity checks)
+    "UP",   # pyupgrade (modern Python 3.12+ features)
+    "SIM",  # flake8-simplify (simplifies code patterns)
+    "RET"   # flake8-return (consistent return statements)
+]
+
+lint.ignore = [
+    # Rules we want to ignore go in here.
+    # Always provide a comment explaining why.
+]