python-best-practices

---
name: python-best-practices
description: Pythonic code with modern type hints, dataclasses, async patterns, packaging, and testing
---

# Python Best Practices

## Type Hints (3.12+ Syntax)

```python
# Use built-in generics (3.9+), no need for typing.List, typing.Dict
def process_items(items: list[str]) -> dict[str, int]:
    return {item: len(item) for item in items}

# Union with | syntax (3.10+)
def find_user(user_id: int) -> User | None:
    ...

# Type parameter syntax (3.12+)
type Vec