Build Python bindings

The extension, crates/datui-pyo3, builds with maturin from python/. It is not a member of the Cargo workspace. For the installed package, see Use datui from Python and the Python API.

Set up

python -m venv .venv
.venv/bin/pip install maturin "polars==1.43.*" "pytest>=7.0"

It also needs Rust and the Python headers (python3-dev on Debian and Ubuntu). The setup script installs these into .venv too.

Build and test

The datui command the wheel installs runs a bundled binary, found beside the package rather than on PATH. Build it, copy it in, then build the extension:

cargo build
mkdir -p python/datui_bin
cp target/debug/datui python/datui_bin/
cp LICENSE python/LICENSE
cd python && ../.venv/bin/maturin develop && cd ..
.venv/bin/pytest python/tests/ -v

On Windows, copy target/debug/datui.exe. Add --release to maturin develop for an optimized build. The tests cover imports, options, invalid input and serialized plans; where there is a pseudo-terminal, they also open the TUI and check that a captured frame outlives it, and that the Python API page lists every keyword.

Run

import polars as pl
import datui

datui.view(pl.DataFrame({"a": [1, 2, 3], "b": ["x", "y", "z"]}))

q closes the view. The docs’ Python blocks run with .venv/bin/python scripts/docs/doc_examples.py --python, with this build installed.

Polars compatibility

Python frames cross into the extension as serialized LazyFrame plans. Rust Polars 0.55 is paired with Python Polars 1.43. The wheel declares polars>=1.38 with no upper bound, so installing it does not prove every plan reads. Use the paired version when debugging a plan that does not.

The bridge checks the plan’s DSL version and replaces its per-commit schema hash with the receiver’s; capture does the same in reverse. That handles differing build hashes; it does not translate incompatible plans.

When the Rust Polars moves, change these together:

Run the Python tests after changing either side of the bridge.