MCP Server for Apache Airflow

--- description: globs: *.py alwaysApply: false --- At the start of your every response, say "APPLIED PYTHON RULE". # Python Language Rule ## Key Principles - Write concise, technical Python code with accurate examples. - Use functional programming; prefer functions over classes where possible. - Prefer iteration and modularization over code duplication. - Use descriptive variable names with auxiliary verbs (e.g., is_active, has_permission). - Use lowercase_with_underscores for variables, functions, and file names. - Follow PEP 8 style guidelines. ## Python Language Guidelines - Use `def` for functions, `async def` for asynchronous operations. - Use type hints for all function signatures and variables where helpful. - Use f-strings for string formatting. - Prefer list/dict comprehensions over loops when readable. - Use `with` statements for resource management (files, connections). - Use `*args` and `**kwargs` appropriately for flexible function signatures. ## Code Style (Ruff Configuration) Follow these ruff settings for consistent style: - Line length: 120 characters - Target Python version: 3.9+ - Enable: pycodestyle errors/warnings (E, W), pyflakes (F), isort (I), flake8-comprehensions (C), flake8-bugbear (B) - Known first-party imports: ["src"] - Combine imports as single statements and force sort within sections - Allow unused imports in `__init__.py` files ## Error Handling - Handle errors and edge cases at the start of functions (guard clauses). - Use early returns for error conditions; avoid deep nesting and unnecessary `else`. - Place the happy path last in the function. - Use specific exception types rather than bare `except:`. - Implement proper exception handling with meaningful error messages. - Use `try`/`except`/`finally` blocks appropriately. - **Keep try-except blocks minimal** - cover only the specific operations that can fail. ## Code Structure - **Put constants (strings, string templates, etc.) at the top of the file** after imports. - Import standard library modules first, then third-party, then local imports. - **Caller should come before callee** - define functions before they are called. - Use docstrings for functions and classes following PEP 257. - Keep functions small and focused on a single responsibility. - Use meaningful function and variable names that explain intent. - Avoid global variables; pass data through function parameters. ## Python Conventions - Use `if __name__ == "__main__":` for script entry points. - Prefer `is` and `is not` for `None` comparisons. - Use `enumerate()` instead of manual counter variables. - Use `zip()` for parallel iteration. - Prefer `pathlib` over `os.path` for file operations. - Use context managers for resource cleanup. ## Testing Guidelines - Create comprehensive unit tests for all modules using the `pytest` framework. - Place test files directly in the test directory without mirroring subdirectories (e.g., `src/main.py` → `test/test_main.py`). - Use descriptive test method names that clearly indicate what is being tested. - Include `__init__.py` files in test directories to make them proper Python packages. - Mock external dependencies and side effects using `unittest.mock.patch` and `MagicMock`. - Test both happy path and error conditions, including edge cases and exception handling. - Use pytest fixtures for test setup and shared test data. - Ensure tests are isolated and don't depend on external state or other tests. - Include tests for CLI interfaces using `click.testing.CliRunner` with pytest fixtures. - Verify function behavior, return types, and side effects in tests using assert statements. - Use `pytest.mark.parametrize` for testing multiple input combinations efficiently. - Add integration tests with `pytest.mark.integration` for complex workflows and API interactions. - Use `conftest.py` for shared fixtures and test configuration. - Organize tests in classes when testing related functionality together.