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langchain/langchain/embeddings/aleph_alpha.py

214 lines
7.5 KiB
Python

from typing import Any, Dict, List, Optional
from pydantic import BaseModel, root_validator
from langchain.embeddings.base import Embeddings
from langchain.utils import get_from_dict_or_env
class AlephAlphaAsymmetricSemanticEmbedding(BaseModel, Embeddings):
"""
Wrapper for Aleph Alpha's Asymmetric Embeddings
AA provides you with an endpoint to embed a document and a query.
The models were optimized to make the embeddings of documents and
the query for a document as similar as possible.
To learn more, check out: https://docs.aleph-alpha.com/docs/tasks/semantic_embed/
Example:
.. code-block:: python
from aleph_alpha import AlephAlphaAsymmetricSemanticEmbedding
embeddings = AlephAlphaSymmetricSemanticEmbedding()
document = "This is a content of the document"
query = "What is the content of the document?"
doc_result = embeddings.embed_documents([document])
query_result = embeddings.embed_query(query)
"""
client: Any #: :meta private:
model: Optional[str] = "luminous-base"
"""Model name to use."""
hosting: Optional[str] = "https://api.aleph-alpha.com"
"""Optional parameter that specifies which datacenters may process the request."""
normalize: Optional[bool] = True
"""Should returned embeddings be normalized"""
compress_to_size: Optional[int] = 128
"""Should the returned embeddings come back as an original 5120-dim vector,
or should it be compressed to 128-dim."""
contextual_control_threshold: Optional[int] = None
"""Attention control parameters only apply to those tokens that have
explicitly been set in the request."""
control_log_additive: Optional[bool] = True
"""Apply controls on prompt items by adding the log(control_factor)
to attention scores."""
aleph_alpha_api_key: Optional[str] = None
"""API key for Aleph Alpha API."""
@root_validator()
def validate_environment(cls, values: Dict) -> Dict:
"""Validate that api key and python package exists in environment."""
aleph_alpha_api_key = get_from_dict_or_env(
values, "aleph_alpha_api_key", "ALEPH_ALPHA_API_KEY"
)
try:
from aleph_alpha_client import Client
except ImportError:
raise ValueError(
"Could not import aleph_alpha_client python package. "
"Please install it with `pip install aleph_alpha_client`."
)
values["client"] = Client(token=aleph_alpha_api_key)
return values
def embed_documents(self, texts: List[str]) -> List[List[float]]:
"""Call out to Aleph Alpha's asymmetric Document endpoint.
Args:
texts: The list of texts to embed.
Returns:
List of embeddings, one for each text.
"""
try:
from aleph_alpha_client import (
Prompt,
SemanticEmbeddingRequest,
SemanticRepresentation,
)
except ImportError:
raise ValueError(
"Could not import aleph_alpha_client python package. "
"Please install it with `pip install aleph_alpha_client`."
)
document_embeddings = []
for text in texts:
document_params = {
"prompt": Prompt.from_text(text),
"representation": SemanticRepresentation.Document,
"compress_to_size": self.compress_to_size,
"normalize": self.normalize,
"contextual_control_threshold": self.contextual_control_threshold,
"control_log_additive": self.control_log_additive,
}
document_request = SemanticEmbeddingRequest(**document_params)
document_response = self.client.semantic_embed(
request=document_request, model=self.model
)
document_embeddings.append(document_response.embedding)
return document_embeddings
def embed_query(self, text: str) -> List[float]:
"""Call out to Aleph Alpha's asymmetric, query embedding endpoint
Args:
text: The text to embed.
Returns:
Embeddings for the text.
"""
try:
from aleph_alpha_client import (
Prompt,
SemanticEmbeddingRequest,
SemanticRepresentation,
)
except ImportError:
raise ValueError(
"Could not import aleph_alpha_client python package. "
"Please install it with `pip install aleph_alpha_client`."
)
symmetric_params = {
"prompt": Prompt.from_text(text),
"representation": SemanticRepresentation.Query,
"compress_to_size": self.compress_to_size,
"normalize": self.normalize,
"contextual_control_threshold": self.contextual_control_threshold,
"control_log_additive": self.control_log_additive,
}
symmetric_request = SemanticEmbeddingRequest(**symmetric_params)
symmetric_response = self.client.semantic_embed(
request=symmetric_request, model=self.model
)
return symmetric_response.embedding
class AlephAlphaSymmetricSemanticEmbedding(AlephAlphaAsymmetricSemanticEmbedding):
"""The symmetric version of the Aleph Alpha's semantic embeddings.
The main difference is that here, both the documents and
queries are embedded with a SemanticRepresentation.Symmetric
Example:
.. code-block:: python
from aleph_alpha import AlephAlphaSymmetricSemanticEmbedding
embeddings = AlephAlphaAsymmetricSemanticEmbedding()
text = "This is a test text"
doc_result = embeddings.embed_documents([text])
query_result = embeddings.embed_query(text)
"""
def _embed(self, text: str) -> List[float]:
try:
from aleph_alpha_client import (
Prompt,
SemanticEmbeddingRequest,
SemanticRepresentation,
)
except ImportError:
raise ValueError(
"Could not import aleph_alpha_client python package. "
"Please install it with `pip install aleph_alpha_client`."
)
query_params = {
"prompt": Prompt.from_text(text),
"representation": SemanticRepresentation.Symmetric,
"compress_to_size": self.compress_to_size,
"normalize": self.normalize,
"contextual_control_threshold": self.contextual_control_threshold,
"control_log_additive": self.control_log_additive,
}
query_request = SemanticEmbeddingRequest(**query_params)
query_response = self.client.semantic_embed(
request=query_request, model=self.model
)
return query_response.embedding
def embed_documents(self, texts: List[str]) -> List[List[float]]:
"""Call out to Aleph Alpha's Document endpoint.
Args:
texts: The list of texts to embed.
Returns:
List of embeddings, one for each text.
"""
document_embeddings = []
for text in texts:
document_embeddings.append(self._embed(text))
return document_embeddings
def embed_query(self, text: str) -> List[float]:
"""Call out to Aleph Alpha's asymmetric, query embedding endpoint
Args:
text: The text to embed.
Returns:
Embeddings for the text.
"""
return self._embed(text)