Python Best Practices

Professional Python

• PEP 8: Python style guide — 4-space indentation, snake_case for functions/variables, PascalCase for classes, UPPER_CASE for constants. Use Black formatter for automatic enforcement
• Type Hints: def greet(name: str) -> str — document expected types. mypy checks types statically. Use for function signatures, class attributes, and complex data structures
• Virtual Environments: python -m venv .venv — isolated package installations per project. pip freeze > requirements.txt for reproducibility. Poetry for modern dependency management
• Code Quality: ruff (fast Python linter, replaces flake8/isort/pyflint), Black (code formatter), mypy (type checker), pre-commit hooks (run checks before every commit)
• Context Managers: with open('file.txt') as f: — automatic resource cleanup. Create custom with @contextmanager decorator or __enter__/__exit__ methods
• Comprehensions: [x**2 for x in range(10) if x > 5] — concise list creation. Dict comprehensions: {k: v for k, v in pairs}. Generator expressions: sum(x**2 for x in range(10)) — memory efficient
• Decorators: @login_required, @cache_result — modify function behavior without changing code. Create custom: def decorator(func): def wrapper(*args, **kwargs): ... return wrapper