How to Add Extra Data to a Python Package
Today, I learned how to include external files in a Python package using uv and the hatchling build backend. My goal was to add a directory containing sample fixture data to the package. Here’s the resulting pyproject.toml file:
[build-system]
requires = ["hatchling"]
build-backend = "hatchling.build"
[tool.hatch.build.targets.sdist]
packages = ["src/mypackage"]
[tool.hatch.build.targets.sdist.force-include]
"data/fixtures" = "mypackage/fixtures" # Include the fixtures directory in the sdist
[tool.hatch.build.targets.wheel]
packages = ["src/mypackage"]
[tool.hatch.build.targets.wheel.force-include]
"data/fixtures" = "mypackage/fixtures" # Include the fixtures directory in the wheel
This turned out to be surprisingly tricky to get right, and the toml file doesn’t make it immediately clear which paths are the source and which are the target in the sdist and wheel. So, here’s an overview of the directory structure:
project_root/
├── src/
│ └── mypackage/
│ ├── __init__.py
│ ├── module1.py
│ └── fixtures/ # Included as mypackage/fixtures by pyproject.toml
│ ├── fixture1.json
│ └── fixture2.json
├── data/
│ └── fixtures/
│ ├── fixture1.json
│ └── fixture2.json
├── pyproject.toml
└── README.md
