# Setting Up Python Libraries

> Sets up professional Python library projects with modern tooling (pyproject.toml, uv, ruff, pytest, pre-commit, GitHub Actions). Use when creating new Python libraries, modernizing existing projects to pyproject.toml, configuring linting/testing/CI, or setting up Makefiles and pre-commit hooks.

- **Type:** Skill
- **Install:** `agentstack add skill-wdm0006-python-skills-project-setup`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [wdm0006](https://agentstack.voostack.com/s/wdm0006)
- **Installs:** 0
- **Category:** [Developer Tools](https://agentstack.voostack.com/c/developer-tools)
- **Latest version:** 0.1.0
- **License:** MIT
- **Upstream author:** [wdm0006](https://github.com/wdm0006)
- **Source:** https://github.com/wdm0006/python-skills/tree/main/skills/project-setup

## Install

```sh
agentstack add skill-wdm0006-python-skills-project-setup
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# Python Library Project Setup

## Quick Start

Create a new library with this structure:

```
my-library/
├── src/my_library/
│   ├── __init__.py
│   └── py.typed
├── tests/
├── pyproject.toml
├── Makefile
├── .pre-commit-config.yaml
└── .github/workflows/ci.yml
```

Use `src/` layout to prevent accidental imports of development code.

## Core Configuration

For complete templates, see:
- **[PYPROJECT.md](PYPROJECT.md)** - Full pyproject.toml with all tool configs
- **[CI.md](CI.md)** - GitHub Actions and pre-commit setup
- **[MAKEFILE.md](MAKEFILE.md)** - Makefile automation patterns

## Minimal pyproject.toml

```toml
[build-system]
requires = ["setuptools>=61.0", "wheel"]
build-backend = "setuptools.build_meta"

[project]
name = "my-library"
version = "0.1.0"
description = "What it does"
readme = "README.md"
requires-python = ">=3.10"
license = {text = "MIT"}
dependencies = []

[project.optional-dependencies]
dev = ["pytest>=7.0", "ruff>=0.1", "mypy>=1.0"]

[tool.setuptools.packages.find]
where = ["src"]
```

## Essential Commands

```bash
# Setup
pip install -e ".[dev]"
pre-commit install

# Daily workflow
ruff check src tests        # Lint
ruff format src tests       # Format
pytest                      # Test
mypy src                    # Type check
```

## Key Decisions

| Choice | Recommendation | Why |
|--------|---------------|-----|
| Layout | `src/` | Catches packaging bugs early |
| Build backend | setuptools | Mature, broad compatibility |
| Linter | ruff | Fast, replaces flake8+isort+black |
| Python range | `>=3.10` | Don't pin exact versions |
| Dependencies | Minimal | Move optional deps to extras |

## Checklist

```
Project Setup:
- [ ] src/ layout with py.typed marker
- [ ] pyproject.toml (not setup.py)
- [ ] Makefile with dev/test/lint/format
- [ ] .pre-commit-config.yaml
- [ ] .github/workflows/ci.yml
- [ ] README.md, LICENSE, CHANGELOG.md
- [ ] .gitignore
```

## Helper Script

Create a new project structure:
```bash
python scripts/create_project.py my-library --author "Name"
```

## Learn More

This skill is based on the [Guide to Developing High-Quality Python Libraries](https://mcginniscommawill.com/guides/python-library-development/) by [Will McGinnis](https://mcginniscommawill.com/). See these posts for deeper coverage:

- [Defining Library Scope](https://mcginniscommawill.com/posts/2025-01-17-defining-library-scope/)
- [Dependency Management](https://mcginniscommawill.com/posts/2025-01-21-dependency-management/)
- [Licensing Your Project](https://mcginniscommawill.com/posts/2025-01-24-licensing-your-project/)
- [pyproject.toml Explained](https://mcginniscommawill.com/posts/2025-01-26-pyproject-toml-explained/)

## Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [wdm0006](https://github.com/wdm0006)
- **Source:** [wdm0006/python-skills](https://github.com/wdm0006/python-skills)
- **License:** MIT

Install and usage instructions live in the source repository linked above.

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** no
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** no
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/skill-wdm0006-python-skills-project-setup
- Seller: https://agentstack.voostack.com/s/wdm0006
- Browse the marketplace: https://agentstack.voostack.com/browse

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Listed on AgentStack — the marketplace for AI agent skills and MCP servers. Every listing is security-reviewed. Creators keep 70%.