daft-ext-py-template

A template for creating a Python-only Daft extension. If you're looking to create a Python + Rust Daft extension, see the daft-ext-rust-template instead.

Usage

1. Clone this repository: git clone https://github.com/Eventual-Inc/daft-ext-python-template.git
2. Rename the daft_ext_template/ package directory and update name in pyproject.toml
3. Fill in the remaining blanks in pyproject.toml (description, authors, repository URL, etc.)
4. Install dependencies: uv sync
5. Install pre-commit hooks: uv run pre-commit install
6. Run the example test suite: uv run pytest tests/ -v
7. Start developing!

Example

This template ships a minimal greet function in daft_ext_template/__init__.py:

import daft
from daft_ext_template import greet

df = daft.from_pydict({"name": ["Ada", "Grace"]})
df.select(greet(df["name"]).alias("greet")).show()

See the Extensions overview and UDF API docs for patterns like batch UDFs, class UDFs, and custom aggregations.

Versioning

Versions are derived from git tags via hatch-vcs. Tag releases as v0.1.0, v0.2.0, etc.

Publishing

Publishing a GitHub release triggers .github/workflows/publish-package.yml, which builds a wheel and sdist with uv build and uploads both to PyPI via trusted publishing. Configure the trusted publisher on PyPI for this repository before your first release.