Python Dev Agent Skill

>- Python 开发规范。当用户操作 .py、pyproject.toml、requirements.txt、setup.py 文件，或涉及 FastAPI、Django、Flask、pytest、asyncio 开发时触发。包含 PEP 8 风格、类型注解、异常处理、测试规范、异步编程、性能优化等。

931 tokens

context cost

the whole folder, loaded on every use

files

instructions only

copies elsewhere

how many repositories repackaged it

1027

stars on the repo

on the repository, not the skill itself

Install

one command, takes just this skill from the repository

npx skills add https://github.com/doccker/cc-use-exp --skill python-dev

The instruction itself

2 sections, as written by the author

Python 开发规范

> 参考来源: PEP 8、Google Python Style Guide

工具链

black .                              # 代码格式化
isort .                              # import 排序
mypy .                               # 静态类型检查
ruff check .                         # 快速 linter（推荐）
pytest -v                            # 运行测试
pytest --cov=src                     # 覆盖率

命名约定

| 类型 | 规则 | 示例 |

|------|------|------|

| 模块/包 | 小写下划线 | user_service.py |

| 类名 | 大驼峰 | UserService, HttpClient |

| 函数/变量 | 小写下划线 | get_user_by_id, user_name |

| 常量 | 全大写下划线 | MAX_RETRY_COUNT |

| 私有 | 单下划线前缀 | _internal_method |

类型注解

from typing import Optional, List, Dict
from dataclasses import dataclass

@dataclass
class User:
    id: int
    name: str
    email: Optional[str] = None

def find_user_by_id(user_id: int) -> Optional[User]:
    ...

# Python 3.10+ 可用新语法
def greet(name: str | None = None) -> str:
    return f"Hello, {name or 'World'}"

异常处理

# ✅ 好：捕获具体异常
try:
    user = repository.find_by_id(user_id)
except DatabaseError as e:
    logger.error(f"Failed to find user {user_id}: {e}")
    raise ServiceError(f"Database error: {e}") from e

# ✅ 好：上下文管理器
with open("file.txt", "r") as f:
    content = f.read()

# ❌ 差：裸 except
try:
    do_something()
except:
    pass

测试规范（pytest）

import pytest
from unittest.mock import Mock

class TestUserService:
    @pytest.fixture
    def user_service(self):
        repository = Mock()
        return UserService(repository)

    def test_find_by_id_returns_user(self, user_service):
        expected = User(id=1, name="test")
        user_service.repository.find_by_id.return_value = expected
        result = user_service.find_by_id(1)
        assert result == expected

# 参数化测试
@pytest.mark.parametrize("input,expected", [
    (1, 1), (2, 4), (3, 9),
])
def test_square(input, expected):
    assert square(input) == expected

异步编程

import asyncio

async def fetch_user(user_id: int) -> User:
    async with aiohttp.ClientSession() as session:
        async with session.get(f"/api/users/{user_id}") as response:
            data = await response.json()
            return User(**data)

# 限制并发数
async def fetch_with_limit(user_ids: list[int], limit: int = 10) -> list[User]:
    semaphore = asyncio.Semaphore(limit)
    async def fetch_one(uid: int) -> User:
        async with semaphore:
            return await fetch_user(uid)
    return await asyncio.gather(*[fetch_one(uid) for uid in user_ids])

性能优化

| 场景 | 方案 |

|------|------|

| 大数据处理 | 使用生成器 yield |

| 字符串拼接 | 使用 ''.join() |

| 查找操作 | 使用 set 或 dict |

| 并发 I/O | 使用 asyncio |

| CPU 密集 | 使用 multiprocessing |

项目结构

project/
├── src/
│   └── myproject/
│       ├── __init__.py
│       ├── models/
│       ├── services/
│       └── utils/
├── tests/
│   ├── conftest.py
│   └── test_*.py
├── pyproject.toml
└── README.md

How to use it

Copy the folder

Take doccker/cc-use-exp-.cursor-python-dev from the repository into ~/.claude/skills for personal use, or into .claude/skills inside a project.

Check the name does not clash

The agent identifies a skill by the name field in its header. Two skills with the same name cannot sit side by side — one of them will be ignored.