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lancedb/python/python/lancedb/embeddings/cohere.py

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Python

# Copyright (c) 2023. LanceDB Developers
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import os
from typing import ClassVar, List, Union
import numpy as np
from ..util import attempt_import_or_raise
from .base import TextEmbeddingFunction
from .registry import register
from .utils import api_key_not_found_help, TEXT
@register("cohere")
class CohereEmbeddingFunction(TextEmbeddingFunction):
"""
An embedding function that uses the Cohere API
https://docs.cohere.com/docs/multilingual-language-models
Parameters
----------
name: str, default "embed-multilingual-v2.0"
The name of the model to use. List of acceptable models:
* embed-english-v3.0
* embed-multilingual-v3.0
* embed-english-light-v3.0
* embed-multilingual-light-v3.0
* embed-english-v2.0
* embed-english-light-v2.0
* embed-multilingual-v2.0
source_input_type: str, default "search_document"
The input type for the source column in the database
query_input_type: str, default "search_query"
The input type for the query column in the database
Cohere supports following input types:
| Input Type | Description |
|-------------------------|---------------------------------------|
| "`search_document`" | Used for embeddings stored in a vector|
| | database for search use-cases. |
| "`search_query`" | Used for embeddings of search queries |
| | run against a vector DB |
| "`semantic_similarity`" | Specifies the given text will be used |
| | for Semantic Textual Similarity (STS) |
| "`classification`" | Used for embeddings passed through a |
| | text classifier. |
| "`clustering`" | Used for the embeddings run through a |
| | clustering algorithm |
Examples
--------
import lancedb
from lancedb.pydantic import LanceModel, Vector
from lancedb.embeddings import EmbeddingFunctionRegistry
cohere = EmbeddingFunctionRegistry
.get_instance()
.get("cohere")
.create(name="embed-multilingual-v2.0")
class TextModel(LanceModel):
text: str = cohere.SourceField()
vector: Vector(cohere.ndims()) = cohere.VectorField()
data = [ { "text": "hello world" },
{ "text": "goodbye world" }]
db = lancedb.connect("~/.lancedb")
tbl = db.create_table("test", schema=TextModel, mode="overwrite")
tbl.add(data)
"""
name: str = "embed-multilingual-v2.0"
source_input_type: str = "search_document"
query_input_type: str = "search_query"
client: ClassVar = None
def ndims(self):
# TODO: fix hardcoding
if self.name in [
"embed-english-v3.0",
"embed-multilingual-v3.0",
"embed-english-light-v2.0",
]:
return 1024
elif self.name in ["embed-english-light-v3.0", "embed-multilingual-light-v3.0"]:
return 384
elif self.name == "embed-english-v2.0":
return 4096
elif self.name == "embed-multilingual-v2.0":
return 768
else:
raise ValueError(f"Model {self.name} not supported")
def compute_query_embeddings(self, query: str, *args, **kwargs) -> List[np.array]:
return self.compute_source_embeddings(query, input_type=self.query_input_type)
def compute_source_embeddings(self, texts: TEXT, *args, **kwargs) -> List[np.array]:
texts = self.sanitize_input(texts)
input_type = (
kwargs.get("input_type") or self.source_input_type
) # assume source input type if not passed by `compute_query_embeddings`
return self.generate_embeddings(texts, input_type=input_type)
def generate_embeddings(
self, texts: Union[List[str], np.ndarray], *args, **kwargs
) -> List[np.array]:
"""
Get the embeddings for the given texts
Parameters
----------
texts: list[str] or np.ndarray (of str)
The texts to embed
"""
self._init_client()
rs = CohereEmbeddingFunction.client.embed(
texts=texts, model=self.name, **kwargs
)
return [emb for emb in rs.embeddings]
def _init_client(self):
cohere = attempt_import_or_raise("cohere")
if CohereEmbeddingFunction.client is None:
if os.environ.get("COHERE_API_KEY") is None:
api_key_not_found_help("cohere")
CohereEmbeddingFunction.client = cohere.Client(os.environ["COHERE_API_KEY"])