Files
lancedb/python
Will Jones 5a1015ba72 docs(python): fill gaps in the Python API reference (#3746)
`docs/src/python/python.md` is the whole Python API reference, but it is
maintained by hand and had drifted from the public API. Anything not
listed there simply doesn't get rendered, so a number of public,
documented, tested APIs were invisible to users — most notably branch
management, where `diff` and `merge` live.

I audited every public symbol reachable from `lancedb` and its
subpackages against the `:::` directives on the page. This adds the
missing ones:

- **Branching** — `Branches`, `AsyncBranches` (`list` / `create` /
`checkout` / `delete` / `diff` / `merge`)
- **Tables** — `TableStatistics` (returned by `Table.stats()`; the
fragment-level stats classes were already listed)
- **Full text queries** — `FullTextQuery`, `MatchQuery`, `PhraseQuery`,
`BoostQuery`, `MultiMatchQuery`, `BooleanQuery`, `FullTextOperator`,
`Occur`
- **Querying** — `LanceEmptyQueryBuilder`, `LanceTakeQueryBuilder`,
`AsyncTakeQuery`
- **Indices** — `Fm` (the FM-index for substring search), `IndexConfig`
- **Blobs** — `blob`, `BlobType`, `BlobFile`
- **Namespaces** — `connect_namespace`, `connect_namespace_async`, and
both namespace connection classes
- **Remote config** — `TlsConfig`, `HeaderProvider`, `OAuthConfig`,
`OAuthFlowType`
- **Rerankers** — the `Reranker` base class plus `JinaReranker`,
`RRFReranker`, `MRRReranker`, `AnswerdotaiRerankers`,
`VoyageAIReranker`, `WatsonxReranker` (5 of 12 were listed)
- **Embeddings** — `get_registry`, `register`, and the 14 embedding
functions that were missing (3 of 17 were listed)
- **PyTorch** — `StreamingDataset` and the permutation API it is built
on
- **Misc** — `Session`, `tokenize`, `FtsToken`, `pydantic.Vector`,
`pydantic.MultiVector`, `instrument_lancedb_metrics`, and the two
exception types

It also repairs cross-references in docstrings that no longer resolve:
links into guide pages that have since moved to lancedb.com
(`querying-an-ann-index`, `experimental-full-text-search`),
`lance.dataset` references with no inventory behind them, and the
relative targets `[Table](Table)` and `[PyArrow Table](pyarrow.Table)`.

Deliberately left out: concrete implementation classes reached through
their abstract base (`LanceTable`, `LanceDBConnection`,
`RemoteDBConnection`), query base classes already covered by
`inherited_members: true`, and internal plumbing such as
`FullTextSearchQuery` and `ColumnOrdering`.

## Testing

The docs job only runs on pushes to `main`, so I built the site locally
and compared against a build of `upstream/main`: every added entry
resolves, and no symbol that was rendered before stopped being rendered
when the four packages moved to automodule. `mkdocs build --strict`
exits 0 on this branch, against 61 warnings on `main`.

## Also in this PR

`lancedb.index`, `lancedb.embeddings`, `lancedb.remote` and
`lancedb.rerankers` are now rendered by a single mkdocstrings directive
each, driven by the module's `__all__`, rather than a hand-maintained
list. These four are where most of the drift was, and `__all__` is
harder to forget than a docs page. `lancedb.embeddings` had no
`__all__`; without one mkdocstrings renders no members at all for a
re-export package, so one is added. AGENTS.md gains a section on how the
page is wired up and how to build the docs locally.

Rendering all that code for the first time surfaced ~100 more build
warnings, which would have made #3707 (turning on `mkdocs build
--strict`) harder to land, so the warning backlog is cleared here too.
97 of the 158 warnings were one systematic false positive — griffe
cannot see the generated `__init__` of a pydantic dataclass, so every
documented parameter looks unknown — switched off via
`warn_unknown_params`. The remaining 61 came from 15 docstrings with
real bugs: prose trailing a `Parameters` section (we were rendering
parameters called `The`, `you` and `To`), types dropped because numpydoc
needs spaces around the colon, `num_partitions, default sqrt(num_rows)`
parsing as a list of names and inventing a `default` parameter, and one
parameter indented five spaces. `mkdocs build --strict` now exits 0.

---

#3747 (the coverage test that keeps this from happening again) is
stacked on this branch, so review it after this one.

---------

Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-07-30 16:50:05 -07:00
..
2025-01-29 08:27:07 -08:00
2024-04-05 16:22:59 -07:00

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.