Source code for langchain.agents.conversational.base

"""一个旨在进行对话并使用工具的代理程序。"""
from __future__ import annotations

from typing import Any, List, Optional, Sequence

from langchain_core._api import deprecated
from langchain_core.callbacks import BaseCallbackManager
from langchain_core.language_models import BaseLanguageModel
from langchain_core.prompts import PromptTemplate
from langchain_core.pydantic_v1 import Field
from langchain_core.tools import BaseTool

from langchain.agents.agent import Agent, AgentOutputParser
from langchain.agents.agent_types import AgentType
from langchain.agents.conversational.output_parser import ConvoOutputParser
from langchain.agents.conversational.prompt import FORMAT_INSTRUCTIONS, PREFIX, SUFFIX
from langchain.agents.utils import validate_tools_single_input
from langchain.chains import LLMChain


[docs]@deprecated("0.1.0", alternative="create_react_agent", removal="0.3.0") class ConversationalAgent(Agent): """一个除了使用工具外还能进行对话的代理程序。""" ai_prefix: str = "AI" """用于AI输出之前的前缀。""" output_parser: AgentOutputParser = Field(default_factory=ConvoOutputParser) """代理的输出解析器。""" @classmethod def _get_default_output_parser( cls, ai_prefix: str = "AI", **kwargs: Any ) -> AgentOutputParser: return ConvoOutputParser(ai_prefix=ai_prefix) @property def _agent_type(self) -> str: """返回代理类型的标识符。""" return AgentType.CONVERSATIONAL_REACT_DESCRIPTION @property def observation_prefix(self) -> str: """要附加到观测值前面的前缀。""" return "Observation: " @property def llm_prefix(self) -> str: """用于在llm调用前附加的前缀。""" return "Thought:"
[docs] @classmethod def create_prompt( cls, tools: Sequence[BaseTool], prefix: str = PREFIX, suffix: str = SUFFIX, format_instructions: str = FORMAT_INSTRUCTIONS, ai_prefix: str = "AI", human_prefix: str = "Human", input_variables: Optional[List[str]] = None, ) -> PromptTemplate: """创建与零次代理相似的提示。 参数: tools:代理将可以访问的工具列表,用于格式化提示。 prefix:工具列表之前要放置的字符串。 suffix:工具列表之后要放置的字符串。 ai_prefix:AI输出之前要使用的字符串。 human_prefix:人类输出之前要使用的字符串。 input_variables:最终提示将期望的输入变量列表。 返回: 从这里的各部分组装而成的PromptTemplate。 """ tool_strings = "\n".join( [f"> {tool.name}: {tool.description}" for tool in tools] ) tool_names = ", ".join([tool.name for tool in tools]) format_instructions = format_instructions.format( tool_names=tool_names, ai_prefix=ai_prefix, human_prefix=human_prefix ) template = "\n\n".join([prefix, tool_strings, format_instructions, suffix]) if input_variables is None: input_variables = ["input", "chat_history", "agent_scratchpad"] return PromptTemplate(template=template, input_variables=input_variables)
@classmethod def _validate_tools(cls, tools: Sequence[BaseTool]) -> None: super()._validate_tools(tools) validate_tools_single_input(cls.__name__, tools)
[docs] @classmethod def from_llm_and_tools( cls, llm: BaseLanguageModel, tools: Sequence[BaseTool], callback_manager: Optional[BaseCallbackManager] = None, output_parser: Optional[AgentOutputParser] = None, prefix: str = PREFIX, suffix: str = SUFFIX, format_instructions: str = FORMAT_INSTRUCTIONS, ai_prefix: str = "AI", human_prefix: str = "Human", input_variables: Optional[List[str]] = None, **kwargs: Any, ) -> Agent: """从LLM和工具构建一个代理。""" cls._validate_tools(tools) prompt = cls.create_prompt( tools, ai_prefix=ai_prefix, human_prefix=human_prefix, prefix=prefix, suffix=suffix, format_instructions=format_instructions, input_variables=input_variables, ) llm_chain = LLMChain( # type: ignore[misc] llm=llm, prompt=prompt, callback_manager=callback_manager, ) tool_names = [tool.name for tool in tools] _output_parser = output_parser or cls._get_default_output_parser( ai_prefix=ai_prefix ) return cls( llm_chain=llm_chain, allowed_tools=tool_names, ai_prefix=ai_prefix, output_parser=_output_parser, **kwargs, )