Source code for langchain.chains.conversation.base

"""链条继续对话并调用LLM。"""
from typing import Dict, List

from langchain_core.memory import BaseMemory
from langchain_core.prompts import BasePromptTemplate
from langchain_core.pydantic_v1 import Extra, Field, root_validator

from langchain.chains.conversation.prompt import PROMPT
from langchain.chains.llm import LLMChain
from langchain.memory.buffer import ConversationBufferMemory


class ConversationChain(LLMChain):
    """链条用于进行对话并从内存中加载上下文。

    示例:
        .. code-block:: python

            from langchain.chains import ConversationChain
            from langchain_community.llms import OpenAI

            conversation = ConversationChain(llm=OpenAI())"""

    memory: BaseMemory = Field(default_factory=ConversationBufferMemory)
    """默认内存存储。"""
    prompt: BasePromptTemplate = PROMPT
    """默认的对话提示。"""

    input_key: str = "input"  #: :meta private:
    output_key: str = "response"  #: :meta private:

    class Config:
        """此pydantic对象的配置。"""

        extra = Extra.forbid
        arbitrary_types_allowed = True

    @classmethod
    def is_lc_serializable(cls) -> bool:
        return False

    @property
    def input_keys(self) -> List[str]:
        """由于某些提示变量来自历史记录，因此使用这个。"""
        return [self.input_key]

    @root_validator()
    def validate_prompt_input_variables(cls, values: Dict) -> Dict:
        """验证提示输入变量是否一致。"""
        memory_keys = values["memory"].memory_variables
        input_key = values["input_key"]
        if input_key in memory_keys:
            raise ValueError(
                f"The input key {input_key} was also found in the memory keys "
                f"({memory_keys}) - please provide keys that don't overlap."
            )
        prompt_variables = values["prompt"].input_variables
        expected_keys = memory_keys + [input_key]
        if set(expected_keys) != set(prompt_variables):
            raise ValueError(
                "Got unexpected prompt input variables. The prompt expects "
                f"{prompt_variables}, but got {memory_keys} as inputs from "
                f"memory, and {input_key} as the normal input key."
            )
        return values