lancedb-gatefixer[bot]
fc44535cee
## Summary - raise a clear `TypeError` when `Vector` is used without a dimension - preserve normal `Vector(dim)` behavior across Pydantic v1 and v2 - add a regression test that defines a model without importing PyArrow ## Root cause Pydantic interpreted the bare `Vector` factory as a callable field type and inspected its postponed annotations in the user model's namespace. Because that namespace did not define LanceDB's internal `pa` alias, model construction failed with the misleading `NameError: name 'pa' is not defined` instead of explaining that `Vector` must be parameterized. The factory now exposes Pydantic's v1 and v2 schema hooks and rejects bare use before signature introspection with guidance to use `Vector(dim)`. ## Validation - `uvx --from 'ruff==0.15.20' ruff check .` - `uvx --from 'ruff==0.15.20' ruff format --check python/python/lancedb/pydantic.py python/python/tests/test_pydantic.py` - `cd python && uv run --extra tests pytest python/tests/test_pydantic.py::test_bare_vector_raises_clear_error -q` - `cd python && uv run --extra tests pytest python/tests/test_pydantic.py -q` - compatibility checks with Pydantic 1.10.22, 2.11.4, and 2.13.4 Fixes #2384 <!-- lance-gatekeeper-fix:v1 agent=71e7473e18c91db5137a3c0d3bb73640 generation=1 --> Co-authored-by: Gatefixer <313497061+lancedb-gatefixer[bot]@users.noreply.github.com>
LanceDB Python SDK
A Python library for LanceDB.
Installation
pip install lancedb
Pre-Haswell x86_64 hosts: lancedb-compat
The default lancedb wheel targets x86-64-haswell (AVX2 + FMA + F16C) for full performance on modern hardware. Pre-Haswell hosts — Intel Sandy Bridge / Ivy Bridge / Westmere; AMD Bulldozer / Piledriver / Steamroller — don't have AVX2 and crash with Illegal instruction at import lancedb.
For those hosts, install the lancedb-compat package instead:
pip install lancedb-compat
Same Python API (import lancedb works as usual). The compat wheel is compiled at the x86-64-v2 baseline (Nehalem-class) and uses runtime SIMD dispatch in the embedded lance crate to pick the right kernel tier (scalar / AVX / AVX+FMA / AVX2+FMA / AVX-512) at load time, so it still goes fast on modern hardware while running cleanly on the pre-Haswell silicon. Use lance.simd_info() from Python to verify which tier was selected.
lancedb and lancedb-compat install to the same lancedb/ namespace and conflict at install time. Pick one. To switch, pip uninstall lancedb first, then pip install lancedb-compat (or vice-versa).
If you need a custom baseline (or lancedb-compat isn't yet published for your platform), build from source with the override:
RUSTFLAGS="-C target-cpu=x86-64-v2" maturin build --release
pip install ./target/wheels/lancedb-*.whl
Preview Releases
Stable releases are created about every 2 weeks. For the latest features and bug fixes, you can install the preview release. These releases receive the same level of testing as stable releases, but are not guaranteed to be available for more than 6 months after they are released. Once your application is stable, we recommend switching to stable releases.
pip install --pre --extra-index-url https://pypi.fury.io/lancedb/ 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
See CONTRIBUTING.md for information on how to contribute to LanceDB.