mirror of
https://github.com/Mintplex-Labs/langchain-python.git
synced 2026-07-19 13:26:32 -04:00
Harrison Chase
524 lines
20 KiB
Python
524 lines
20 KiB
Python
"""OpenAI chat wrapper."""
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from __future__ import annotations
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import logging
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import sys
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from typing import (
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TYPE_CHECKING,
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Any,
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Callable,
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Dict,
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List,
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Mapping,
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Optional,
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Tuple,
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Union,
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)
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from pydantic import Field, root_validator
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from tenacity import (
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before_sleep_log,
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retry,
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retry_if_exception_type,
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stop_after_attempt,
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wait_exponential,
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)
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from langchain.callbacks.manager import (
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AsyncCallbackManagerForLLMRun,
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CallbackManagerForLLMRun,
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)
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from langchain.chat_models.base import BaseChatModel
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from langchain.schema import (
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AIMessage,
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BaseMessage,
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ChatGeneration,
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ChatMessage,
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ChatResult,
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FunctionMessage,
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HumanMessage,
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SystemMessage,
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)
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from langchain.utils import get_from_dict_or_env
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if TYPE_CHECKING:
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import tiktoken
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logger = logging.getLogger(__name__)
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def _import_tiktoken() -> Any:
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try:
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import tiktoken
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except ImportError:
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raise ValueError(
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"Could not import tiktoken python package. "
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"This is needed in order to calculate get_token_ids. "
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"Please install it with `pip install tiktoken`."
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)
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return tiktoken
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def _create_retry_decorator(llm: ChatOpenAI) -> Callable[[Any], Any]:
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import openai
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min_seconds = 1
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max_seconds = 60
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# Wait 2^x * 1 second between each retry starting with
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# 4 seconds, then up to 10 seconds, then 10 seconds afterwards
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return retry(
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reraise=True,
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stop=stop_after_attempt(llm.max_retries),
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wait=wait_exponential(multiplier=1, min=min_seconds, max=max_seconds),
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retry=(
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retry_if_exception_type(openai.error.Timeout)
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| retry_if_exception_type(openai.error.APIError)
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| retry_if_exception_type(openai.error.APIConnectionError)
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| retry_if_exception_type(openai.error.RateLimitError)
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| retry_if_exception_type(openai.error.ServiceUnavailableError)
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),
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before_sleep=before_sleep_log(logger, logging.WARNING),
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)
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async def acompletion_with_retry(llm: ChatOpenAI, **kwargs: Any) -> Any:
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"""Use tenacity to retry the async completion call."""
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retry_decorator = _create_retry_decorator(llm)
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@retry_decorator
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async def _completion_with_retry(**kwargs: Any) -> Any:
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# Use OpenAI's async api https://github.com/openai/openai-python#async-api
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return await llm.client.acreate(**kwargs)
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return await _completion_with_retry(**kwargs)
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def _convert_dict_to_message(_dict: Mapping[str, Any]) -> BaseMessage:
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role = _dict["role"]
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if role == "user":
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return HumanMessage(content=_dict["content"])
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elif role == "assistant":
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content = _dict["content"] or "" # OpenAI returns None for tool invocations
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if _dict.get("function_call"):
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additional_kwargs = {"function_call": dict(_dict["function_call"])}
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else:
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additional_kwargs = {}
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return AIMessage(content=content, additional_kwargs=additional_kwargs)
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elif role == "system":
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return SystemMessage(content=_dict["content"])
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elif role == "function":
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return FunctionMessage(content=_dict["content"], name=_dict["name"])
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else:
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return ChatMessage(content=_dict["content"], role=role)
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def _convert_message_to_dict(message: BaseMessage) -> dict:
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if isinstance(message, ChatMessage):
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message_dict = {"role": message.role, "content": message.content}
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elif isinstance(message, HumanMessage):
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message_dict = {"role": "user", "content": message.content}
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elif isinstance(message, AIMessage):
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message_dict = {"role": "assistant", "content": message.content}
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if "function_call" in message.additional_kwargs:
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message_dict["function_call"] = message.additional_kwargs["function_call"]
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elif isinstance(message, SystemMessage):
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message_dict = {"role": "system", "content": message.content}
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elif isinstance(message, FunctionMessage):
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message_dict = {
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"role": "function",
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"content": message.content,
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"name": message.name,
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}
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else:
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raise ValueError(f"Got unknown type {message}")
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if "name" in message.additional_kwargs:
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message_dict["name"] = message.additional_kwargs["name"]
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return message_dict
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class ChatOpenAI(BaseChatModel):
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"""Wrapper around OpenAI Chat large language models.
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To use, you should have the ``openai`` python package installed, and the
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environment variable ``OPENAI_API_KEY`` set with your API key.
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Any parameters that are valid to be passed to the openai.create call can be passed
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in, even if not explicitly saved on this class.
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Example:
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.. code-block:: python
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from langchain.chat_models import ChatOpenAI
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openai = ChatOpenAI(model_name="gpt-3.5-turbo")
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"""
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@property
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def lc_secrets(self) -> Dict[str, str]:
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return {"openai_api_key": "OPENAI_API_KEY"}
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@property
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def lc_serializable(self) -> bool:
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return True
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client: Any #: :meta private:
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model_name: str = Field(default="gpt-3.5-turbo", alias="model")
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"""Model name to use."""
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temperature: float = 0.7
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"""What sampling temperature to use."""
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model_kwargs: Dict[str, Any] = Field(default_factory=dict)
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"""Holds any model parameters valid for `create` call not explicitly specified."""
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openai_api_key: Optional[str] = None
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"""Base URL path for API requests,
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leave blank if not using a proxy or service emulator."""
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openai_api_base: Optional[str] = None
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openai_organization: Optional[str] = None
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# to support explicit proxy for OpenAI
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openai_proxy: Optional[str] = None
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request_timeout: Optional[Union[float, Tuple[float, float]]] = None
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"""Timeout for requests to OpenAI completion API. Default is 600 seconds."""
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max_retries: int = 6
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"""Maximum number of retries to make when generating."""
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streaming: bool = False
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"""Whether to stream the results or not."""
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n: int = 1
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"""Number of chat completions to generate for each prompt."""
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max_tokens: Optional[int] = None
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"""Maximum number of tokens to generate."""
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tiktoken_model_name: Optional[str] = None
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"""The model name to pass to tiktoken when using this class.
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Tiktoken is used to count the number of tokens in documents to constrain
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them to be under a certain limit. By default, when set to None, this will
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be the same as the embedding model name. However, there are some cases
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where you may want to use this Embedding class with a model name not
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supported by tiktoken. This can include when using Azure embeddings or
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when using one of the many model providers that expose an OpenAI-like
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API but with different models. In those cases, in order to avoid erroring
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when tiktoken is called, you can specify a model name to use here."""
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class Config:
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"""Configuration for this pydantic object."""
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allow_population_by_field_name = True
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@root_validator(pre=True)
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def build_extra(cls, values: Dict[str, Any]) -> Dict[str, Any]:
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"""Build extra kwargs from additional params that were passed in."""
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all_required_field_names = cls.all_required_field_names()
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extra = values.get("model_kwargs", {})
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for field_name in list(values):
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if field_name in extra:
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raise ValueError(f"Found {field_name} supplied twice.")
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if field_name not in all_required_field_names:
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logger.warning(
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f"""WARNING! {field_name} is not default parameter.
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{field_name} was transferred to model_kwargs.
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Please confirm that {field_name} is what you intended."""
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)
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extra[field_name] = values.pop(field_name)
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invalid_model_kwargs = all_required_field_names.intersection(extra.keys())
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if invalid_model_kwargs:
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raise ValueError(
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f"Parameters {invalid_model_kwargs} should be specified explicitly. "
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f"Instead they were passed in as part of `model_kwargs` parameter."
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)
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values["model_kwargs"] = extra
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return values
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@root_validator()
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def validate_environment(cls, values: Dict) -> Dict:
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"""Validate that api key and python package exists in environment."""
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values["openai_api_key"] = get_from_dict_or_env(
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values, "openai_api_key", "OPENAI_API_KEY"
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)
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values["openai_organization"] = get_from_dict_or_env(
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values,
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"openai_organization",
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"OPENAI_ORGANIZATION",
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default="",
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)
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values["openai_api_base"] = get_from_dict_or_env(
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values,
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"openai_api_base",
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"OPENAI_API_BASE",
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default="",
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)
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values["openai_proxy"] = get_from_dict_or_env(
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values,
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"openai_proxy",
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"OPENAI_PROXY",
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default="",
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)
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try:
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import openai
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except ImportError:
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raise ValueError(
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"Could not import openai python package. "
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"Please install it with `pip install openai`."
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)
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try:
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values["client"] = openai.ChatCompletion
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except AttributeError:
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raise ValueError(
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"`openai` has no `ChatCompletion` attribute, this is likely "
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"due to an old version of the openai package. Try upgrading it "
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"with `pip install --upgrade openai`."
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)
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if values["n"] < 1:
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raise ValueError("n must be at least 1.")
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if values["n"] > 1 and values["streaming"]:
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raise ValueError("n must be 1 when streaming.")
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return values
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@property
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def _default_params(self) -> Dict[str, Any]:
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"""Get the default parameters for calling OpenAI API."""
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return {
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"model": self.model_name,
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"request_timeout": self.request_timeout,
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"max_tokens": self.max_tokens,
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"stream": self.streaming,
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"n": self.n,
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"temperature": self.temperature,
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**self.model_kwargs,
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}
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def _create_retry_decorator(self) -> Callable[[Any], Any]:
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import openai
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min_seconds = 1
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max_seconds = 60
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# Wait 2^x * 1 second between each retry starting with
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# 4 seconds, then up to 10 seconds, then 10 seconds afterwards
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return retry(
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reraise=True,
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stop=stop_after_attempt(self.max_retries),
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wait=wait_exponential(multiplier=1, min=min_seconds, max=max_seconds),
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retry=(
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retry_if_exception_type(openai.error.Timeout)
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| retry_if_exception_type(openai.error.APIError)
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| retry_if_exception_type(openai.error.APIConnectionError)
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| retry_if_exception_type(openai.error.RateLimitError)
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| retry_if_exception_type(openai.error.ServiceUnavailableError)
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),
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before_sleep=before_sleep_log(logger, logging.WARNING),
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)
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def completion_with_retry(self, **kwargs: Any) -> Any:
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"""Use tenacity to retry the completion call."""
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retry_decorator = self._create_retry_decorator()
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@retry_decorator
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def _completion_with_retry(**kwargs: Any) -> Any:
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return self.client.create(**kwargs)
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return _completion_with_retry(**kwargs)
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def _combine_llm_outputs(self, llm_outputs: List[Optional[dict]]) -> dict:
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overall_token_usage: dict = {}
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for output in llm_outputs:
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if output is None:
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# Happens in streaming
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continue
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token_usage = output["token_usage"]
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for k, v in token_usage.items():
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if k in overall_token_usage:
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overall_token_usage[k] += v
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else:
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overall_token_usage[k] = v
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return {"token_usage": overall_token_usage, "model_name": self.model_name}
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def _generate(
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self,
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messages: List[BaseMessage],
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stop: Optional[List[str]] = None,
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run_manager: Optional[CallbackManagerForLLMRun] = None,
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**kwargs: Any,
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) -> ChatResult:
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message_dicts, params = self._create_message_dicts(messages, stop)
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params = {**params, **kwargs}
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if self.streaming:
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inner_completion = ""
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role = "assistant"
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params["stream"] = True
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function_call: Optional[dict] = None
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for stream_resp in self.completion_with_retry(
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messages=message_dicts, **params
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):
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role = stream_resp["choices"][0]["delta"].get("role", role)
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token = stream_resp["choices"][0]["delta"].get("content") or ""
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inner_completion += token
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_function_call = stream_resp["choices"][0]["delta"].get("function_call")
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if _function_call:
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if function_call is None:
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function_call = _function_call
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else:
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function_call["arguments"] += _function_call["arguments"]
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if run_manager:
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run_manager.on_llm_new_token(token)
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message = _convert_dict_to_message(
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{
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"content": inner_completion,
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"role": role,
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"function_call": function_call,
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}
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)
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return ChatResult(generations=[ChatGeneration(message=message)])
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response = self.completion_with_retry(messages=message_dicts, **params)
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return self._create_chat_result(response)
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def _create_message_dicts(
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self, messages: List[BaseMessage], stop: Optional[List[str]]
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) -> Tuple[List[Dict[str, Any]], Dict[str, Any]]:
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params = dict(self._invocation_params)
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if stop is not None:
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if "stop" in params:
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raise ValueError("`stop` found in both the input and default params.")
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params["stop"] = stop
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message_dicts = [_convert_message_to_dict(m) for m in messages]
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return message_dicts, params
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def _create_chat_result(self, response: Mapping[str, Any]) -> ChatResult:
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generations = []
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for res in response["choices"]:
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message = _convert_dict_to_message(res["message"])
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gen = ChatGeneration(message=message)
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generations.append(gen)
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llm_output = {"token_usage": response["usage"], "model_name": self.model_name}
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return ChatResult(generations=generations, llm_output=llm_output)
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async def _agenerate(
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self,
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messages: List[BaseMessage],
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stop: Optional[List[str]] = None,
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run_manager: Optional[AsyncCallbackManagerForLLMRun] = None,
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**kwargs: Any,
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) -> ChatResult:
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message_dicts, params = self._create_message_dicts(messages, stop)
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params = {**params, **kwargs}
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if self.streaming:
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inner_completion = ""
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role = "assistant"
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params["stream"] = True
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function_call: Optional[dict] = None
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async for stream_resp in await acompletion_with_retry(
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self, messages=message_dicts, **params
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):
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role = stream_resp["choices"][0]["delta"].get("role", role)
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token = stream_resp["choices"][0]["delta"].get("content", "")
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inner_completion += token or ""
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_function_call = stream_resp["choices"][0]["delta"].get("function_call")
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if _function_call:
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if function_call is None:
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function_call = _function_call
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else:
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function_call["arguments"] += _function_call["arguments"]
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if run_manager:
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await run_manager.on_llm_new_token(token)
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message = _convert_dict_to_message(
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{
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"content": inner_completion,
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"role": role,
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"function_call": function_call,
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}
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)
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return ChatResult(generations=[ChatGeneration(message=message)])
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else:
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response = await acompletion_with_retry(
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self, messages=message_dicts, **params
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)
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return self._create_chat_result(response)
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@property
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def _identifying_params(self) -> Mapping[str, Any]:
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"""Get the identifying parameters."""
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return {**{"model_name": self.model_name}, **self._default_params}
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@property
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def _invocation_params(self) -> Mapping[str, Any]:
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"""Get the parameters used to invoke the model."""
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openai_creds: Dict[str, Any] = {
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"api_key": self.openai_api_key,
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"api_base": self.openai_api_base,
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"organization": self.openai_organization,
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"model": self.model_name,
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}
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if self.openai_proxy:
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import openai
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openai.proxy = {"http": self.openai_proxy, "https": self.openai_proxy} # type: ignore[assignment] # noqa: E501
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return {**openai_creds, **self._default_params}
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@property
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def _llm_type(self) -> str:
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"""Return type of chat model."""
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return "openai-chat"
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def _get_encoding_model(self) -> Tuple[str, tiktoken.Encoding]:
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tiktoken_ = _import_tiktoken()
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if self.tiktoken_model_name is not None:
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model = self.tiktoken_model_name
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else:
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model = self.model_name
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if model == "gpt-3.5-turbo":
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# gpt-3.5-turbo may change over time.
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# Returning num tokens assuming gpt-3.5-turbo-0301.
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model = "gpt-3.5-turbo-0301"
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elif model == "gpt-4":
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# gpt-4 may change over time.
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# Returning num tokens assuming gpt-4-0314.
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model = "gpt-4-0314"
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# Returns the number of tokens used by a list of messages.
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try:
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encoding = tiktoken_.encoding_for_model(model)
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except KeyError:
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logger.warning("Warning: model not found. Using cl100k_base encoding.")
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model = "cl100k_base"
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encoding = tiktoken_.get_encoding(model)
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return model, encoding
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def get_token_ids(self, text: str) -> List[int]:
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"""Get the tokens present in the text with tiktoken package."""
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# tiktoken NOT supported for Python 3.7 or below
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if sys.version_info[1] <= 7:
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return super().get_token_ids(text)
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_, encoding_model = self._get_encoding_model()
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return encoding_model.encode(text)
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def get_num_tokens_from_messages(self, messages: List[BaseMessage]) -> int:
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"""Calculate num tokens for gpt-3.5-turbo and gpt-4 with tiktoken package.
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Official documentation: https://github.com/openai/openai-cookbook/blob/
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main/examples/How_to_format_inputs_to_ChatGPT_models.ipynb"""
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if sys.version_info[1] <= 7:
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return super().get_num_tokens_from_messages(messages)
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model, encoding = self._get_encoding_model()
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if model.startswith("gpt-3.5-turbo"):
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# every message follows <im_start>{role/name}\n{content}<im_end>\n
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tokens_per_message = 4
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# if there's a name, the role is omitted
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tokens_per_name = -1
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elif model.startswith("gpt-4"):
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tokens_per_message = 3
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tokens_per_name = 1
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else:
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raise NotImplementedError(
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f"get_num_tokens_from_messages() is not presently implemented "
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f"for model {model}."
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"See https://github.com/openai/openai-python/blob/main/chatml.md for "
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"information on how messages are converted to tokens."
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)
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num_tokens = 0
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messages_dict = [_convert_message_to_dict(m) for m in messages]
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for message in messages_dict:
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num_tokens += tokens_per_message
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for key, value in message.items():
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num_tokens += len(encoding.encode(value))
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if key == "name":
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num_tokens += tokens_per_name
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# every reply is primed with <im_start>assistant
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num_tokens += 3
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return num_tokens
|