python-anti-patterns

# Python Anti-Patterns Checklist

A reference checklist of common mistakes and anti-patterns in Python code. Review this before finalizing implementations to catch issues early.

## When to Use This Skill

- Reviewing code before merge
- Debugging mysterious issues
- Teaching or learning Python best practices
- Establishing team coding standards
- Refactoring legacy code

**Note:** This skill focuses on what to avoid. For guidance on positive patterns and architecture, see the `python-design-patterns` skill.

## Infrastructure Anti-Patterns

### Scattered Timeout/Retry Logic

```python
# BAD: Timeout logic duplicated everywhere
def fetch_user(user_id):
    try:
        return requests.get(url, timeout=30)
    except Timeout:
        logger.warning("Timeout fetching user")
        return None

def fetch_orders(user_id):
    try:
        return requests.get(url, timeout=30)
    except Timeout:
        logger.warning("Timeout fetching orders")
        return None
```

**Fix:** Centralize in decorators or client wrappers.

```python
# GOOD: Centralized retry logic
@retry(stop=stop_after_attempt(3), wait=wait_exponential())
def http_get(url: str) -> Response:
…