Python Library Project Setup
Quick Start
Create a new library with this structure:
code
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 - Full pyproject.toml with all tool configs
- •CI.md - GitHub Actions and pre-commit setup
- •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
code
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"