Python Development Guide

Code Style

• •Follow PEP 8 (enforced by Ruff)
• •Use type hints for all public functions
• •Prefer f-strings over .format() or %

Common Patterns

• •Use dataclasses or Pydantic for data structures
• •Use context managers for resource management
• •Prefer pathlib over os.path

Testing

• •Use pytest with descriptive test function names
• •Use fixtures for test setup
• •Use parametrize for multiple test cases

Error Handling

• •Create custom exceptions inheriting from appropriate base
• •Use raise ... from e to preserve stack traces
• •Document exceptions in docstrings

Type Checking

• •Run mypy --ignore-missing-imports . before committing
• •Use Optional[T] for nullable values
• •Use TypeVar for generic functions