python-packaging

What this skill does

# Python Packaging

Quick reference for building and publishing Python packages with UV and modern build tools.

## When to Use This Skill

| Use this skill when... | Use uv-project-management instead when... |
|---|---|
| Building a wheel/sdist with `uv build` for PyPI distribution | Setting up a new project's pyproject.toml or adding runtime dependencies |
| Publishing a release to PyPI or a private index with `uv publish` | Managing the lockfile or syncing the local virtual environment |
| Configuring entry points, console scripts, or package metadata for distribution | Resolving dependency conflicts or pinning versions for development |

## When This Skill Applies

- Building Python packages (wheels, sdists)
- Publishing to PyPI or private indexes
- Package versioning
- Build system configuration
- Editable installations

## Quick Reference

### Building Packages

```bash
# Build package
uv build

# Build specific formats
uv build --wheel
uv build --sdist

# Output location: dist/
```

### Publishing

```bash
# Publish to PyPI
uv publish

# With token
uv publish --token $PYPI_TOKEN

# To Test PyPI
uv publish --publish-url https://test.pypi.org/legacy/
```

### Package Structure

```
my-package/
├── pyproject.toml
├── README.md
├── LICENSE
├── src/
│   └── my_package/
│       ├── __init__.py
│       ├── __version__.py
│       └── main.py
└── tests/
```

## pyproject.toml Configuration

```toml
[project]
name = "my-package"
version = "0.1.0"
description = "A great package"
readme = "README.md"
requires-python = ">=3.11"
license = {text = "MIT"}
authors = [
    {name = "Your Name", email = "[email protected]"}
]
keywords = ["python", "package"]
classifiers = [
    "Development Status :: 4 - Beta",
    "Intended Audience :: Developers",
    "Programming Language :: Python :: 3",
    "Programming Language :: Python :: 3.11",
]

dependencies = [
    "requests>=2.31.0",
]

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

[project.urls]
Homepage = "https://github.com/user/my-package"
Documentation = "https://my-package.readthedocs.io"
Repository = "https://github.com/user/my-package.git"
Issues = "https://github.com/user/my-package/issues"

[project.scripts]
my-cli = "my_package.cli:main"

[build-system]
requires = ["uv_build>=0.9.2,<0.10.0"]
build-backend = "uv_build"
```

## Versioning

```toml
[project]
version = "0.1.0"  # Manual versioning

# Dynamic versioning (from git tags)
dynamic = ["version"]

[tool.uv]
version-provider = "git"
```

## Entry Points

```toml
[project.scripts]
my-cli = "my_package.cli:main"

[project.gui-scripts]
my-gui = "my_package.gui:main"

[project.entry-points."my_plugin"]
plugin1 = "my_package.plugins:plugin1"
```

## Build Backends

### UV Build (default)

```toml
[build-system]
requires = ["uv_build>=0.9.2,<0.10.0"]
build-backend = "uv_build"
```

### Setuptools

```toml
[build-system]
requires = ["setuptools>=68", "wheel"]
build-backend = "setuptools.build_meta"
```

### Hatchling

```toml
[build-system]
requires = ["hatchling>=1.18"]
build-backend = "hatchling.build"
```

## Common Workflows

### Publish to PyPI

```bash
# 1. Build
uv build

# 2. Check built packages
ls dist/

# 3. Publish
uv publish --token $PYPI_TOKEN
```

### Test PyPI First

```bash
# Publish to Test PyPI
uv publish --publish-url https://test.pypi.org/legacy/ \
           --token $TEST_PYPI_TOKEN

# Test installation
pip install --index-url https://test.pypi.org/simple/ my-package
```

## Package Classifiers

Common classifiers:

```toml
classifiers = [
    # Development Status
    "Development Status :: 3 - Alpha",
    "Development Status :: 4 - Beta",
    "Development Status :: 5 - Production/Stable",

    # Audience
    "Intended Audience :: Developers",
    "Intended Audience :: Science/Research",

    # License
    "License :: OSI Approved :: MIT License",

    # Python Versions
    "Programming Language :: Python :: 3",
    "Programming Language :: Python :: 3.11",
    "Programming Language :: Python :: 3.12",

    # Framework
    "Framework :: Django",
    "Framework :: FastAPI",

    # Topic
    "Topic :: Software Development :: Libraries",
    "Topic :: Scientific/Engineering",
]
```

Full list: https://pypi.org/classifiers/

## See Also

- `uv-project-management` - Project setup and dependencies
- `python-development` - Core Python patterns
- `uv-workspaces` - Building workspace packages

## References

- UV build: https://docs.astral.sh/uv/guides/publish/
- PyPI: https://pypi.org/
- Detailed guide: See REFERENCE.md