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The LanceDB embeddings registry allows users to annotate the pydantic
model used as table schema with the desired embedding function, e.g.:
```python
class Schema(LanceModel):
id: str
vector: Vector(openai.ndims()) = openai.VectorField()
text: str = openai.SourceField()
```
Tables created like this does not require embeddings to be calculated by
the user explicitly, e.g. this works:
```python
table.add([{"id": "foo", "text": "rust all the things"}])
```
However, trying to construct pydantic model instances without vector
doesn't because it's a required field.
Instead, you need add a default value:
```python
class Schema(LanceModel):
id: str
vector: Vector(openai.ndims()) = openai.VectorField(default=None)
text: str = openai.SourceField()
```
then this completes without errors:
```python
table.add([Schema(id="foo", text="rust all the things")])
```
However, all of the vectors are filled with zeros. Instead in
add_vector_col we have to add an additional check so that the embedding
generation is called.
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
matruin 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