---
name: python-skill
description: Python coding best practices and patterns. Use when writing, reviewing, or debugging Python code.
---

# Python Skill

## Type Hints (Python 3.10+)

```python
# Bad
def process(data, callback):
    return callback(data)

# Good
from typing import Callable

def process(data: dict, callback: Callable[[dict], str]) -> str:
    return callback(data)
```

## Dataclasses Over Plain Dicts

```python
from dataclasses import dataclass

@dataclass
class GameFrame:
    timestamp: float
    objects: list[str]
    confidence: float = 1.0
```

## Context Managers for Resources

```python
# Bad
f = open("log.txt")
data = f.read()
f.close()

# Good
with open("log.txt") as f:
    data = f.read()
```

## List Comprehensions vs Loops

```python
# Prefer comprehension for simple transforms
enemies = [obj for obj in objects if obj.type == "enemy"]

# Use loop when logic is complex (>2 conditions)
results = []
for obj in objects:
    if obj.type == "enemy" and obj.visible and obj.distance < 100:
        results.append(obj.position)
```

## Error Handling
```python
# Be specific — never catch bare Exception silently
try:
    frame = capture_screen()
except ScreenCaptureError as e:
    logger.error("Screen capture failed: %s", e)
    raise
```