python

name	python
description	Python development tasks including creating scripts, managing virtual environments, running tests, installing packages, and project setup. Use when working with Python, FastAPI, Django, Flask, or related frameworks.
argument-hint	[command] [args]
allowed-tools	Read, Write, Edit, Grep, Glob, Bash(python:*), Bash(python3:*), Bash(pip:*), Bash(uv:*), Bash(pipenv:*), Bash(pytest:*), Bash(ruff:*), Bash(mypy:*)

Python Development Skill

You are a Python development assistant. When invoked, help with Python tasks following these guidelines.

Project Config

The following is this project's Python configuration. Use these frameworks, paths, and commands instead of defaults:

!cat .claude/skills/python/config.md 2>/dev/null || echo "No project config found — using defaults."

Commands

Based on the arguments provided, perform the appropriate action:

Project Setup

• init - Initialize a Python project with pyproject.toml, src layout, and virtual environment
• venv - Create virtual environment (uses package manager from config)
• install - Install dependencies
• install <pkg> - Install a package
• freeze - Lock/save dependencies

Package Managers (check config.md for which one to use)

uv (default, recommended):

• uv init - Initialize project: uv init
• uv venv - Create venv: uv venv
• uv add <pkg> - Add dependency: uv add <pkg>
• uv add --dev <pkg> - Add dev dependency: uv add --dev <pkg>
• uv sync - Install all dependencies: uv sync
• uv run <cmd> - Run command in venv: uv run <cmd>
• uv lock - Lock dependencies: uv lock
• uv pip install <pkg> - Install via pip compatibility: uv pip install <pkg>

pipenv:

• pipenv init - Initialize: pipenv --python 3.12
• pipenv install - Install from Pipfile: pipenv install
• pipenv install <pkg> - Add dependency: pipenv install <pkg>
• pipenv install --dev <pkg> - Add dev dependency: pipenv install --dev <pkg>
• pipenv shell - Activate venv: pipenv shell
• pipenv run <cmd> - Run command: pipenv run <cmd>
• pipenv lock - Lock dependencies: pipenv lock
• pipenv graph - Show dependency tree: pipenv graph

pip (legacy):

• pip venv - Create venv: python3 -m venv .venv && source .venv/bin/activate
• pip install - Install: pip install -r requirements.txt
• pip install <pkg> - Install package: pip install <pkg>
• pip freeze - Save deps: pip freeze > requirements.txt

Development

• run <file> - Run a Python script: python <file>
• test - Run tests: python -m pytest
• test <path> - Run specific tests: python -m pytest <path> -v
• lint - Run linter: ruff check .
• format - Format code: ruff format .
• typecheck - Type check: mypy .

Frameworks

• fastapi - Create a FastAPI project structure
• django <name> - Create a Django project: django-admin startproject <name>
• flask - Create a Flask project structure

Utilities

• repl - Start Python REPL: python3
• shell - Activate venv and open shell

Conventions

When generating Python code:

1. Use type hints for all function signatures
2. Docstrings in Google style for public functions
3. File structure: flat for small projects, src layout for packages
4. Naming: snake_case for functions/variables, PascalCase for classes
5. Error handling: specific exceptions, not bare except
6. Imports: standard library, third-party, local (separated by blank lines)
7. Testing: pytest with fixtures, parametrize for multiple cases

Project Template (pyproject.toml)

[project]
name = "my-project"
version = "0.1.0"
requires-python = ">=3.12"
dependencies = []

[project.optional-dependencies]
dev = [
    "pytest",
    "ruff",
    "mypy",
]

[tool.ruff]
target-version = "py312"
line-length = 88

[tool.pytest.ini_options]
testpaths = ["tests"]

FastAPI Template

from fastapi import FastAPI

app = FastAPI()


@app.get("/health")
async def health() -> dict[str, str]:
    return {"status": "ok"}

Test Template

import pytest


class TestFeature:
    def test_should_do_something(self):
        # Arrange
        input_data = ...

        # Act
        result = function(input_data)

        # Assert
        assert result == expected