Source code for langchain.evaluation.qa.generate_chain
"""LLM Chain for generating examples for question answering."""
from __future__ import annotations
from typing import Any
from langchain_core.language_models import BaseLanguageModel
from langchain_core.output_parsers import BaseLLMOutputParser
from langchain_core.pydantic_v1 import Field
from langchain.chains.llm import LLMChain
from langchain.evaluation.qa.generate_prompt import PROMPT
from langchain.output_parsers.regex import RegexParser
_QA_OUTPUT_PARSER = RegexParser(
regex=r"QUESTION: (.*?)\n+ANSWER: (.*)", output_keys=["query", "answer"]
)
[docs]class QAGenerateChain(LLMChain):
"""LLM Chain for generating examples for question answering."""
output_parser: BaseLLMOutputParser = Field(default=_QA_OUTPUT_PARSER)
output_key: str = "qa_pairs"
@classmethod
def is_lc_serializable(cls) -> bool:
return False
[docs] @classmethod
def from_llm(cls, llm: BaseLanguageModel, **kwargs: Any) -> QAGenerateChain:
"""Load QA Generate Chain from LLM."""
return cls(llm=llm, prompt=PROMPT, **kwargs)