import typing
from typing import Any, Dict, List, Optional, Sequence
import cohere
from langchain_core.embeddings import Embeddings
from langchain_core.pydantic_v1 import BaseModel, Extra, root_validator
from langchain_core.utils import get_from_dict_or_env
from .utils import _create_retry_decorator
[docs]
class CohereEmbeddings(BaseModel, Embeddings):
"""
Implements the Embeddings interface with Cohere's text representation language
models.
Find out more about us at https://cohere.com and https://huggingface.co/CohereForAI
This implementation uses the Embed API - see https://docs.cohere.com/reference/embed
To use this you'll need to a Cohere API key - either pass it to cohere_api_key
parameter or set the COHERE_API_KEY environment variable.
API keys are available on https://cohere.com - it's free to sign up and trial API
keys work with this implementation.
Basic Example:
.. code-block:: python
cohere_embeddings = CohereEmbeddings(model="embed-english-light-v3.0")
text = "This is a test document."
query_result = cohere_embeddings.embed_query(text)
print(query_result)
doc_result = cohere_embeddings.embed_documents([text])
print(doc_result)
"""
client: Any #: :meta private:
"""Cohere client."""
async_client: Any #: :meta private:
"""Cohere async client."""
model: Optional[str] = None
"""Model name to use. It is mandatory to specify the model name."""
truncate: Optional[str] = None
"""Truncate embeddings that are too long from start or end ("NONE"|"START"|"END")"""
cohere_api_key: Optional[str] = None
embedding_types: Optional[Sequence[str]] = ["float"]
"Specifies the types of embeddings you want to get back"
max_retries: int = 3
"""Maximum number of retries to make when generating."""
request_timeout: Optional[float] = None
"""Timeout in seconds for the Cohere API request."""
user_agent: str = "langchain:partner"
"""Identifier for the application making the request."""
base_url: Optional[str] = None
"""Override the default Cohere API URL."""
class Config:
"""Configuration for this pydantic object."""
arbitrary_types_allowed = True
extra = Extra.forbid
@root_validator()
def validate_environment(cls, values: Dict) -> Dict:
"""Validate that api key and python package exists in environment."""
cohere_api_key = get_from_dict_or_env(
values, "cohere_api_key", "COHERE_API_KEY"
)
request_timeout = values.get("request_timeout")
client_name = values["user_agent"]
values["client"] = cohere.Client(
cohere_api_key,
timeout=request_timeout,
client_name=client_name,
base_url=values["base_url"],
)
values["async_client"] = cohere.AsyncClient(
cohere_api_key,
timeout=request_timeout,
client_name=client_name,
base_url=values["base_url"],
)
return values
@root_validator()
def validate_model_specified(cls, values: Dict) -> Dict:
"""Validate that model is specified."""
model = values.get("model")
if not model:
raise ValueError(
"Did not find `model`! Please "
" pass `model` as a named parameter."
" Please check out"
" https://docs.cohere.com/reference/embed"
" for available models."
)
return values
[docs]
def embed_with_retry(self, **kwargs: Any) -> Any:
"""Use tenacity to retry the embed call."""
retry_decorator = _create_retry_decorator(self.max_retries)
@retry_decorator
def _embed_with_retry(**kwargs: Any) -> Any:
return self.client.embed(**kwargs)
return _embed_with_retry(**kwargs)
[docs]
def aembed_with_retry(self, **kwargs: Any) -> Any:
"""Use tenacity to retry the embed call."""
retry_decorator = _create_retry_decorator(self.max_retries)
@retry_decorator
async def _embed_with_retry(**kwargs: Any) -> Any:
return await self.async_client.embed(**kwargs)
return _embed_with_retry(**kwargs)
[docs]
def embed(
self,
texts: List[str],
*,
input_type: typing.Optional[cohere.EmbedInputType] = None,
) -> List[List[float]]:
embeddings = self.embed_with_retry(
model=self.model,
texts=texts,
input_type=input_type,
truncate=self.truncate,
embedding_types=self.embedding_types,
).embeddings
return [list(map(float, e)) for e in embeddings]
[docs]
async def aembed(
self,
texts: List[str],
*,
input_type: typing.Optional[cohere.EmbedInputType] = None,
) -> List[List[float]]:
embeddings = (
await self.aembed_with_retry(
model=self.model,
texts=texts,
input_type=input_type,
truncate=self.truncate,
embedding_types=self.embedding_types,
)
).embeddings
return [list(map(float, e)) for e in embeddings]
[docs]
def embed_documents(self, texts: List[str]) -> List[List[float]]:
"""Embed a list of document texts.
Args:
texts: The list of texts to embed.
Returns:
List of embeddings, one for each text.
"""
return self.embed(texts, input_type="search_document")
[docs]
async def aembed_documents(self, texts: List[str]) -> List[List[float]]:
"""Async call out to Cohere's embedding endpoint.
Args:
texts: The list of texts to embed.
Returns:
List of embeddings, one for each text.
"""
return await self.aembed(texts, input_type="search_document")
[docs]
def embed_query(self, text: str) -> List[float]:
"""Call out to Cohere's embedding endpoint.
Args:
text: The text to embed.
Returns:
Embeddings for the text.
"""
return self.embed([text], input_type="search_query")[0]
[docs]
async def aembed_query(self, text: str) -> List[float]:
"""Async call out to Cohere's embedding endpoint.
Args:
text: The text to embed.
Returns:
Embeddings for the text.
"""
return (await self.aembed([text], input_type="search_query"))[0]
