Source code for langchain.agents.mrkl.base
"""Attempt to implement MRKL systems as described in arxiv.org/pdf/2205.00445.pdf."""
from __future__ import annotations
from typing import Any, Callable, List, NamedTuple, Optional, Sequence
from langchain.agents.agent import Agent, AgentExecutor, AgentOutputParser
from langchain.agents.agent_types import AgentType
from langchain.agents.mrkl.output_parser import MRKLOutputParser
from langchain.agents.mrkl.prompt import FORMAT_INSTRUCTIONS, PREFIX, SUFFIX
from langchain.agents.tools import Tool
from langchain.agents.utils import validate_tools_single_input
from langchain.callbacks.base import BaseCallbackManager
from langchain.chains import LLMChain
from langchain.prompts import PromptTemplate
from langchain.pydantic_v1 import Field
from langchain.schema.language_model import BaseLanguageModel
from langchain.tools.base import BaseTool
[docs]class ChainConfig(NamedTuple):
    """Configuration for chain to use in MRKL system.
    Args:
        action_name: Name of the action.
        action: Action function to call.
        action_description: Description of the action.
    """
    action_name: str
    action: Callable
    action_description: str
[docs]class ZeroShotAgent(Agent):
    """Agent for the MRKL chain."""
    output_parser: AgentOutputParser = Field(default_factory=MRKLOutputParser)
    @classmethod
    def _get_default_output_parser(cls, **kwargs: Any) -> AgentOutputParser:
        return MRKLOutputParser()
    @property
    def _agent_type(self) -> str:
        """Return Identifier of agent type."""
        return AgentType.ZERO_SHOT_REACT_DESCRIPTION
    @property