"""Wrapper around OpenAI embedding models."""
from __future__ import annotations
import logging
from typing import Any, Callable, Dict, List, Optional
import numpy as np
from pydantic import BaseModel, Extra, root_validator
from tenacity import (
before_sleep_log,
retry,
retry_if_exception_type,
stop_after_attempt,
wait_exponential,
)
from langchain.embeddings.base import Embeddings
from langchain.utils import get_from_dict_or_env
logger = logging.getLogger(__name__)
def _create_retry_decorator(embeddings: OpenAIEmbeddings) -> Callable[[Any], Any]:
import openai
min_seconds = 4
max_seconds = 10
# Wait 2^x * 1 second between each retry starting with
# 4 seconds, then up to 10 seconds, then 10 seconds afterwards
return retry(
reraise=True,
stop=stop_after_attempt(embeddings.max_retries),
wait=wait_exponential(multiplier=1, min=min_seconds, max=max_seconds),
retry=(
retry_if_exception_type(openai.error.Timeout)
| retry_if_exception_type(openai.error.APIError)
| retry_if_exception_type(openai.error.APIConnectionError)
| retry_if_exception_type(openai.error.RateLimitError)
| retry_if_exception_type(openai.error.ServiceUnavailableError)
),
before_sleep=before_sleep_log(logger, logging.WARNING),
)
def embed_with_retry(embeddings: OpenAIEmbeddings, **kwargs: Any) -> Any:
"""Use tenacity to retry the completion call."""
retry_decorator = _create_retry_decorator(embeddings)
@retry_decorator
def _completion_with_retry(**kwargs: Any) -> Any:
return embeddings.client.create(**kwargs)
return _completion_with_retry(**kwargs)
[docs]class OpenAIEmbeddings(BaseModel, Embeddings):
"""Wrapper around OpenAI embedding models.
To use, you should have the ``openai`` python package installed, and the
environment variable ``OPENAI_API_KEY`` set with your API key or pass it
as a named parameter to the constructor.
Example:
.. code-block:: python
from langchain.embeddings import OpenAIEmbeddings
openai = OpenAIEmbeddings(openai_api_key="my-api-key")
"""
client: Any #: :meta private:
document_model_name: str = "text-embedding-ada-002"
query_model_name: str = "text-embedding-ada-002"
embedding_ctx_length: int = -1
openai_api_key: Optional[str] = None
chunk_size: int = 1000
"""Maximum number of texts to embed in each batch"""
max_retries: int = 6
"""Maximum number of retries to make when generating."""
class Config:
"""Configuration for this pydantic object."""
extra = Extra.forbid
# TODO: deprecate this
@root_validator(pre=True)
def get_model_names(cls, values: Dict) -> Dict:
"""Get model names from just old model name."""
if "model_name" in values:
if "document_model_name" in values:
raise ValueError(
"Both `model_name` and `document_model_name` were provided, "
"but only one should be."
)
if "query_model_name" in values:
raise ValueError(
"Both `model_name` and `query_model_name` were provided, "
"but only one should be."
)
model_name = values.pop("model_name")
values["document_model_name"] = f"text-search-{model_name}-doc-001"
values["query_model_name"] = f"text-search-{model_name}-query-001"
return values
@root_validator()
def validate_environment(cls, values: Dict) -> Dict:
"""Validate that api key and python package exists in environment."""
openai_api_key = get_from_dict_or_env(
values, "openai_api_key", "OPENAI_API_KEY"
)
try:
import openai
openai.api_key = openai_api_key
values["client"] = openai.Embedding
except ImportError:
raise ValueError(
"Could not import openai python package. "
"Please it install it with `pip install openai`."
)
return values
# please refer to
# https://github.com/openai/openai-cookbook/blob/main/examples/Embedding_long_inputs.ipynb
def _get_len_safe_embeddings(
self, texts: List[str], *, engine: str, chunk_size: Optional[int] = None
) -> List[List[float]]:
embeddings: List[List[float]] = [[] for i in range(len(texts))]
try:
import tiktoken
tokens = []
indices = []
encoding = tiktoken.model.encoding_for_model(self.document_model_name)
for i, text in enumerate(texts):
# replace newlines, which can negatively affect performance.
text = text.replace("\n", " ")
token = encoding.encode(text)
for j in range(0, len(token), self.embedding_ctx_length):
tokens += [token[j : j + self.embedding_ctx_length]]
indices += [i]
batched_embeddings = []
_chunk_size = chunk_size or self.chunk_size
for i in range(0, len(tokens), _chunk_size):
response = embed_with_retry(
self,
input=tokens[i : i + _chunk_size],
engine=self.document_model_name,
)
batched_embeddings += [r["embedding"] for r in response["data"]]
results: List[List[List[float]]] = [[] for i in range(len(texts))]
lens: List[List[int]] = [[] for i in range(len(texts))]
for i in range(len(indices)):
results[indices[i]].append(batched_embeddings[i])
lens[indices[i]].append(len(batched_embeddings[i]))
for i in range(len(texts)):
average = np.average(results[i], axis=0, weights=lens[i])
embeddings[i] = (average / np.linalg.norm(average)).tolist()
return embeddings
except ImportError:
raise ValueError(
"Could not import tiktoken python package. "
"This is needed in order to for OpenAIEmbeddings. "
"Please it install it with `pip install tiktoken`."
)
def _embedding_func(self, text: str, *, engine: str) -> List[float]:
"""Call out to OpenAI's embedding endpoint."""
# replace newlines, which can negatively affect performance.
if self.embedding_ctx_length > 0:
return self._get_len_safe_embeddings([text], engine=engine)[0]
else:
text = text.replace("\n", " ")
return embed_with_retry(self, input=[text], engine=engine)["data"][0][
"embedding"
]
[docs] def embed_documents(
self, texts: List[str], chunk_size: Optional[int] = 0
) -> List[List[float]]:
"""Call out to OpenAI's embedding endpoint for embedding search docs.
Args:
texts: The list of texts to embed.
chunk_size: The chunk size of embeddings. If None, will use the chunk size
specified by the class.
Returns:
List of embeddings, one for each text.
"""
# handle large batches of texts
if self.embedding_ctx_length > 0:
return self._get_len_safe_embeddings(texts, engine=self.document_model_name)
else:
results = []
_chunk_size = chunk_size or self.chunk_size
for i in range(0, len(texts), _chunk_size):
response = embed_with_retry(
self,
input=texts[i : i + _chunk_size],
engine=self.document_model_name,
)
results += [r["embedding"] for r in response["data"]]
return results
[docs] def embed_query(self, text: str) -> List[float]:
"""Call out to OpenAI's embedding endpoint for embedding query text.
Args:
text: The text to embed.
Returns:
Embeddings for the text.
"""
embedding = self._embedding_func(text, engine=self.query_model_name)
return embedding