lancedb/python

LanceDB

A Python library for LanceDB.

Installation

pip install lancedb

Usage

Basic Example

import lancedb
db = lancedb.connect('<PATH_TO_LANCEDB_DATASET>')
table = db.open_table('my_table')
results = table.search([0.1, 0.3]).limit(20).to_list()
print(results)

Development

LanceDb is based on the rust crate lancedb and is built with maturin. In order to build with maturin you will either need a conda environment or a virtual environment (venv).

python -m venv venv
. ./venv/bin/activate

Install the necessary packages:

python -m pip install .[tests,dev]

To build the python package you can use maturin:

# This will build the rust bindings and place them in the appropriate place
# in your venv or conda environment
maturin develop

To run the unit tests:

pytest

To run the doc tests:

pytest --doctest-modules python/lancedb

To run linter and automatically fix all errors:

ruff format python
ruff --fix python

If any packages are missing, install them with:

pip install <PACKAGE_NAME>

---

For Windows users, there may be errors when installing packages, so these commands may be helpful:

Activate the virtual environment:

. .\venv\Scripts\activate

You may need to run the installs separately:

pip install -e .[tests]
pip install -e .[dev]

tantivy requires rust to be installed, so install it with conda, as it doesn't support windows installation:

pip install wheel
pip install cargo
conda install rust
pip install tantivy