from typing import Any, Dict, List, Optional
import requests
from langchain_core.embeddings import Embeddings
from langchain_core.pydantic_v1 import BaseModel, Extra, Field, SecretStr
DEFAULT_MODEL_NAME = "sentence-transformers/all-mpnet-base-v2"
DEFAULT_INSTRUCT_MODEL = "hkunlp/instructor-large"
DEFAULT_BGE_MODEL = "BAAI/bge-large-en"
DEFAULT_EMBED_INSTRUCTION = "Represent the document for retrieval: "
DEFAULT_QUERY_INSTRUCTION = (
"Represent the question for retrieving supporting documents: "
)
DEFAULT_QUERY_BGE_INSTRUCTION_EN = (
"Represent this question for searching relevant passages: "
)
DEFAULT_QUERY_BGE_INSTRUCTION_ZH = "为这个句子生成表示以用于检索相关文章："
[docs]class HuggingFaceEmbeddings(BaseModel, Embeddings):
"""HuggingFace sentence_transformers embedding models.
To use, you should have the ``sentence_transformers`` python package installed.
Example:
.. code-block:: python
from langchain_community.embeddings import HuggingFaceEmbeddings
model_name = "sentence-transformers/all-mpnet-base-v2"
model_kwargs = {'device': 'cpu'}
encode_kwargs = {'normalize_embeddings': False}
hf = HuggingFaceEmbeddings(
model_name=model_name,
model_kwargs=model_kwargs,
encode_kwargs=encode_kwargs
)
"""
client: Any #: :meta private:
model_name: str = DEFAULT_MODEL_NAME
"""Model name to use."""
cache_folder: Optional[str] = None
"""Path to store models.
Can be also set by SENTENCE_TRANSFORMERS_HOME environment variable."""
model_kwargs: Dict[str, Any] = Field(default_factory=dict)
"""Keyword arguments to pass to the Sentence Transformer model, such as `device`,
`prompts`, `default_prompt_name`, `revision`, `trust_remote_code`, or `token`.
See also the Sentence Transformer documentation: https://sbert.net/docs/package_reference/SentenceTransformer.html#sentence_transformers.SentenceTransformer"""
encode_kwargs: Dict[str, Any] = Field(default_factory=dict)
"""Keyword arguments to pass when calling the `encode` method of the Sentence
Transformer model, such as `prompt_name`, `prompt`, `batch_size`, `precision`,
`normalize_embeddings`, and more.
See also the Sentence Transformer documentation: https://sbert.net/docs/package_reference/SentenceTransformer.html#sentence_transformers.SentenceTransformer.encode"""
multi_process: bool = False
"""Run encode() on multiple GPUs."""
show_progress: bool = False
"""Whether to show a progress bar."""
def __init__(self, **kwargs: Any):
"""Initialize the sentence_transformer."""
super().__init__(**kwargs)
try:
import sentence_transformers
except ImportError as exc:
raise ImportError(
"Could not import sentence_transformers python package. "
"Please install it with `pip install sentence-transformers`."
) from exc
self.client = sentence_transformers.SentenceTransformer(
self.model_name, cache_folder=self.cache_folder, **self.model_kwargs
)
class Config:
"""Configuration for this pydantic object."""
extra = Extra.forbid
[docs] def embed_documents(self, texts: List[str]) -> List[List[float]]:
"""Compute doc embeddings using a HuggingFace transformer model.
Args:
texts: The list of texts to embed.
Returns:
List of embeddings, one for each text.
"""
import sentence_transformers
texts = list(map(lambda x: x.replace("\n", " "), texts))
if self.multi_process:
pool = self.client.start_multi_process_pool()
embeddings = self.client.encode_multi_process(texts, pool)
sentence_transformers.SentenceTransformer.stop_multi_process_pool(pool)
else:
embeddings = self.client.encode(
texts, show_progress_bar=self.show_progress, **self.encode_kwargs
)
return embeddings.tolist()
[docs] def embed_query(self, text: str) -> List[float]:
"""Compute query embeddings using a HuggingFace transformer model.
Args:
text: The text to embed.
Returns:
Embeddings for the text.
"""
return self.embed_documents([text])[0]
[docs]class HuggingFaceInstructEmbeddings(BaseModel, Embeddings):
"""Wrapper around sentence_transformers embedding models.
To use, you should have the ``sentence_transformers``
and ``InstructorEmbedding`` python packages installed.
Example:
.. code-block:: python
from langchain_community.embeddings import HuggingFaceInstructEmbeddings
model_name = "hkunlp/instructor-large"
model_kwargs = {'device': 'cpu'}
encode_kwargs = {'normalize_embeddings': True}
hf = HuggingFaceInstructEmbeddings(
model_name=model_name,
model_kwargs=model_kwargs,
encode_kwargs=encode_kwargs
)
"""
client: Any #: :meta private:
model_name: str = DEFAULT_INSTRUCT_MODEL
"""Model name to use."""
cache_folder: Optional[str] = None
"""Path to store models.
Can be also set by SENTENCE_TRANSFORMERS_HOME environment variable."""
model_kwargs: Dict[str, Any] = Field(default_factory=dict)
"""Keyword arguments to pass to the model."""
encode_kwargs: Dict[str, Any] = Field(default_factory=dict)
"""Keyword arguments to pass when calling the `encode` method of the model."""
embed_instruction: str = DEFAULT_EMBED_INSTRUCTION
"""Instruction to use for embedding documents."""
query_instruction: str = DEFAULT_QUERY_INSTRUCTION
"""Instruction to use for embedding query."""
def __init__(self, **kwargs: Any):
"""Initialize the sentence_transformer."""
super().__init__(**kwargs)
try:
from InstructorEmbedding import INSTRUCTOR
self.client = INSTRUCTOR(
self.model_name, cache_folder=self.cache_folder, **self.model_kwargs
)
except ImportError as e:
raise ImportError("Dependencies for InstructorEmbedding not found.") from e
class Config:
"""Configuration for this pydantic object."""
extra = Extra.forbid
[docs] def embed_documents(self, texts: List[str]) -> List[List[float]]:
"""Compute doc embeddings using a HuggingFace instruct model.
Args:
texts: The list of texts to embed.
Returns:
List of embeddings, one for each text.
"""
instruction_pairs = [[self.embed_instruction, text] for text in texts]
embeddings = self.client.encode(instruction_pairs, **self.encode_kwargs)
return embeddings.tolist()
[docs] def embed_query(self, text: str) -> List[float]:
"""Compute query embeddings using a HuggingFace instruct model.
Args:
text: The text to embed.
Returns:
Embeddings for the text.
"""
instruction_pair = [self.query_instruction, text]
embedding = self.client.encode([instruction_pair], **self.encode_kwargs)[0]
return embedding.tolist()
[docs]class HuggingFaceBgeEmbeddings(BaseModel, Embeddings):
"""HuggingFace sentence_transformers embedding models.
To use, you should have the ``sentence_transformers`` python package installed.
To use Nomic, make sure the version of ``sentence_transformers`` >= 2.3.0.
Bge Example:
.. code-block:: python
from langchain_community.embeddings import HuggingFaceBgeEmbeddings
model_name = "BAAI/bge-large-en"
model_kwargs = {'device': 'cpu'}
encode_kwargs = {'normalize_embeddings': True}
hf = HuggingFaceBgeEmbeddings(
model_name=model_name,
model_kwargs=model_kwargs,
encode_kwargs=encode_kwargs
)
Nomic Example:
.. code-block:: python
from langchain_community.embeddings import HuggingFaceBgeEmbeddings
model_name = "nomic-ai/nomic-embed-text-v1"
model_kwargs = {
'device': 'cpu',
'trust_remote_code':True
}
encode_kwargs = {'normalize_embeddings': True}
hf = HuggingFaceBgeEmbeddings(
model_name=model_name,
model_kwargs=model_kwargs,
encode_kwargs=encode_kwargs,
query_instruction = "search_query:",
embed_instruction = "search_document:"
)
"""
client: Any #: :meta private:
model_name: str = DEFAULT_BGE_MODEL
"""Model name to use."""
cache_folder: Optional[str] = None
"""Path to store models.
Can be also set by SENTENCE_TRANSFORMERS_HOME environment variable."""
model_kwargs: Dict[str, Any] = Field(default_factory=dict)
"""Keyword arguments to pass to the model."""
encode_kwargs: Dict[str, Any] = Field(default_factory=dict)
"""Keyword arguments to pass when calling the `encode` method of the model."""
query_instruction: str = DEFAULT_QUERY_BGE_INSTRUCTION_EN
"""Instruction to use for embedding query."""
embed_instruction: str = ""
"""Instruction to use for embedding document."""
def __init__(self, **kwargs: Any):
"""Initialize the sentence_transformer."""
super().__init__(**kwargs)
try:
import sentence_transformers
except ImportError as exc:
raise ImportError(
"Could not import sentence_transformers python package. "
"Please install it with `pip install sentence_transformers`."
) from exc
self.client = sentence_transformers.SentenceTransformer(
self.model_name, cache_folder=self.cache_folder, **self.model_kwargs
)
if "-zh" in self.model_name:
self.query_instruction = DEFAULT_QUERY_BGE_INSTRUCTION_ZH
class Config:
"""Configuration for this pydantic object."""
extra = Extra.forbid
[docs] def embed_documents(self, texts: List[str]) -> List[List[float]]:
"""Compute doc embeddings using a HuggingFace transformer model.
Args:
texts: The list of texts to embed.
Returns:
List of embeddings, one for each text.
"""
texts = [self.embed_instruction + t.replace("\n", " ") for t in texts]
embeddings = self.client.encode(texts, **self.encode_kwargs)
return embeddings.tolist()
[docs] def embed_query(self, text: str) -> List[float]:
"""Compute query embeddings using a HuggingFace transformer model.
Args:
text: The text to embed.
Returns:
Embeddings for the text.
"""
text = text.replace("\n", " ")
embedding = self.client.encode(
self.query_instruction + text, **self.encode_kwargs
)
return embedding.tolist()
[docs]class HuggingFaceInferenceAPIEmbeddings(BaseModel, Embeddings):
"""Embed texts using the HuggingFace API.
Requires a HuggingFace Inference API key and a model name.
"""
api_key: SecretStr
"""Your API key for the HuggingFace Inference API."""
model_name: str = "sentence-transformers/all-MiniLM-L6-v2"
"""The name of the model to use for text embeddings."""
api_url: Optional[str] = None
"""Custom inference endpoint url. None for using default public url."""
additional_headers: Dict[str, str] = {}
"""Pass additional headers to the requests library if needed."""
@property
def _api_url(self) -> str:
return self.api_url or self._default_api_url
@property
def _default_api_url(self) -> str:
return (
"https://api-inference.huggingface.co"
"/pipeline"
"/feature-extraction"
f"/{self.model_name}"
)
@property
def _headers(self) -> dict:
return {
"Authorization": f"Bearer {self.api_key.get_secret_value()}",
**self.additional_headers,
}
[docs] def embed_documents(self, texts: List[str]) -> List[List[float]]:
"""Get the embeddings for a list of texts.
Args:
texts (Documents): A list of texts to get embeddings for.
Returns:
Embedded texts as List[List[float]], where each inner List[float]
corresponds to a single input text.
Example:
.. code-block:: python
from langchain_community.embeddings import HuggingFaceInferenceAPIEmbeddings
hf_embeddings = HuggingFaceInferenceAPIEmbeddings(
api_key="your_api_key",
model_name="sentence-transformers/all-MiniLM-l6-v2"
)
texts = ["Hello, world!", "How are you?"]
hf_embeddings.embed_documents(texts)
""" # noqa: E501
response = requests.post(
self._api_url,
headers=self._headers,
json={
"inputs": texts,
"options": {"wait_for_model": True, "use_cache": True},
},
)
return response.json()
[docs] def embed_query(self, text: str) -> List[float]:
"""Compute query embeddings using a HuggingFace transformer model.
Args:
text: The text to embed.
Returns:
Embeddings for the text.
"""
return self.embed_documents([text])[0]