---
name: python-packaging-744653d7bca3
description: Create distributable Python packages with proper project structure, setup.py/pyproject.toml, and publishing to PyPI. Use when packaging Python libraries, creating CLI tools, or distributing Python code.
---

# Python Packaging

Comprehensive guide to creating, structuring, and distributing Python packages using modern packaging tools, pyproject.toml, and publishing to PyPI.

## When to Use This Skill

- Creating Python libraries for distribution
- Building command-line tools with entry points
- Publishing packages to PyPI or private repositories
- Setting up Python project structure
- Creating installable packages with dependencies
- Building wheels and source distributions
- Versioning and releasing Python packages
- Creating namespace packages
- Implementing package metadata and classifiers

## Core Concepts

### 1. Package Structure

- **Source layout**: `src/package_name/` (recommended)
- **Flat layout**: `package_name/` (simpler but less flexible)
- **Package metadata**: pyproject.toml, setup.py, or setup.cfg
- **Distribution formats**: wheel (.whl) and source distribution (.tar.gz)

### 2. Modern Packaging Standards

- **PEP 517/518**: Build system requirements
- **PEP 621**: Metadata in pyproject.toml
- **PEP 660**: Editable installs
- **pyproject.toml**: Single source of configuration

### 3. Build Backends

- **setuptools**: Traditional, widely used
- **hatchling**: Modern, opinionated
- **flit**: Lightweight, for pure Python
- **poetry**: Dependency management + packaging

### 4. Distribution

- **PyPI**: Python Package Index (public)
- **TestPyPI**: Testing before production
- **Private repositories**: JFrog, AWS CodeArtifact, etc.

## Quick Start

### Minimal Package Structure

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

### Minimal pyproject.toml

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

[project]
name = "my-package"
version = "0.1.0"
description = "A short description"
authors = [{name = "Your Name", email = "you@example.com"}]
readme = "README.md"
requires-python = ">=3.8"
dependencies = [
    "requests>=2.28.0",
]

[project.optional-dependencies]
dev = [
    "pytest>=7.0",
    "black>=22.0",
]
```

## Package Structure Patterns

### Pattern 1: Source Layout (Recommended)

```
my-package/
├── pyproject.toml
├── README.md
├── LICENSE
├── .gitignore
├── src/
│   └── my_package/
│       ├── __init__.py
│       ├── core.py
│       ├── utils.py
│       └── py.typed          # For type hints
├── tests/
│   ├── __init__.py
│   ├── test_core.py
│   └── test_utils.py
└── docs/
    └── index.md
```

**Advantages:**

- Prevents accidentally importing from source
- Cleaner test imports
- Better isolation

**pyproject.toml for source layout:**

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

### Pattern 2: Flat Layout

```
my-package/
├── pyproject.toml
├── README.md
├── my_package/
│   ├── __init__.py
│   └── module.py
└── tests/
    └── test_module.py
```

**Simpler but:**

- Can import package without installing
- Less professional for libraries

### Pattern 3: Multi-Package Project

```
project/
├── pyproject.toml
├── packages/
│   ├── package-a/
│   │   └── src/
│   │       └── package_a/
│   └── package-b/
│       └── src/
│           └── package_b/
└── tests/
```

## Detailed patterns and worked examples

Detailed pattern documentation lives in `references/details.md`. Read that file when the navigation tier above is insufficient.



---
Source attribution: wshobson
Original project: https://github.com/wshobson/agents/blob/7e2fb559cf4b824b27f1fec49fe88f7511066d26/plugins/python-development/skills/python-packaging/SKILL.md
License: MIT
License information: https://opensource.org/license/mit
Original upstream instructions; downloaded from Mega AI Hub.

## Upstream license notice

MIT License

Copyright (c) 2024 Seth Hobson

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. 


# Mega AI Hub resource metadata

Creator / publisher: wshobson
Original project: https://github.com/wshobson/agents/blob/7e2fb559cf4b824b27f1fec49fe88f7511066d26/plugins/python-development/skills/python-packaging/SKILL.md
Attribution basis: Source repository record

Fields of work: Development & Engineering
Roles: Backend Developer, ML / AI Engineer, Data Engineer
Specialties: Frontend, Word Documents, Git, Testing, Backend
Tools: Pyproject.Toml, Setup.Py, Pypi
Country applicability: Country not specified
Classification basis: Source category, role and specialization labels
Instruction SHA-256: ac827e91679251781eebeb84372cc36fbec8eb38a6772909fb746bb1e930ef12