python-development✓ Pass

SKILL.md Content

---
name: python-development
description: Modern Python development with Python 3.12+, Django, FastAPI, async patterns, and production best practices. Use for Python projects, APIs, data processing, or automation scripts.
source: wshobson/agents
license: MIT
---

# Python Development

## Project Setup

### Modern Python Project Structure
```
my-project/
├── src/
│   └── my_project/
│       ├── __init__.py
│       ├── main.py
│       └── utils.py
├── tests/
│   ├── __init__.py
│   └── test_main.py
├── pyproject.toml
├── README.md
└── .gitignore
```

### pyproject.toml
```toml
[project]
name = "my-project"
version = "0.1.0"
requires-python = ">=3.12"
dependencies = [
    "fastapi>=0.100.0",
    "pydantic>=2.0",
]

[project.optional-dependencies]
dev = [
    "pytest>=7.0",
    "ruff>=0.1.0",
    "mypy>=1.0",
]

[tool.ruff]
line-length = 88
select = ["E", "F", "I", "N", "W"]

[tool.mypy]
strict = true
```

## Type Hints

```python
from typing import TypeVar, Generic
from collections.abc import Sequence

T = TypeVar('T')

def process_items(items: Sequence[str]) -> list[str]:
    return [item.upper() for item in items]

class Repository(Generic[T]):
    def get(self, id: int) -> T | None: ...
    def save(self, item: T) -> T: ...
```

## Async Patterns

```python
import asyncio
from collections.abc import AsyncIterator

async def fetch_all(urls: list[str]) -> list[dict]:
    async with aiohttp.ClientSession() as session:
        tasks = [fetch_one(session, url) for url in urls]
        return await asyncio.gather(*tasks)

async def stream_data() -> AsyncIterator[bytes]:
    async with aiofiles.open('large_file.txt', 'rb') as f:
        async for chunk in f:
            yield chunk
```

## FastAPI Patterns

```python
from fastapi import FastAPI, Depends, HTTPException
from pydantic import BaseModel

app = FastAPI()

class UserCreate(BaseModel):
    email: str
    name: str

class UserResponse(BaseModel):
    id: int
    email: str
    name: str

@app.post("/users", response_model=UserResponse)
async def create_user(
    user: UserCreate,
    db: Database = Depends(get_db)
) -> UserResponse:
    result = await db.users.create(user.model_dump())
    return UserResponse(**result)
```

## Testing

```python
import pytest
from unittest.mock import AsyncMock, patch

@pytest.fixture
def mock_db():
    db = AsyncMock()
    db.users.get.return_value = {"id": 1, "name": "Test"}
    return db

@pytest.mark.asyncio
async def test_get_user(mock_db):
    result = await get_user(1, db=mock_db)
    assert result["name"] == "Test"
    mock_db.users.get.assert_called_once_with(1)
```

## Best Practices

- Use `ruff` for linting and formatting
- Use `mypy` with strict mode
- Prefer `pathlib.Path` over `os.path`
- Use dataclasses or Pydantic for data structures
- Use `asyncio` for I/O-bound operations
- Use `contextlib.asynccontextmanager` for async resources

License

Declared license: MIT

MIT License

Copyright (c) 2026 skillcreatorai

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

View the license in the source repository — the version published there is authoritative.