langchain.output_parsers.boolean — 🦜🔗 LangChain 0.2.0

import re

from langchain_core.output_parsers import BaseOutputParser


[docs]class BooleanOutputParser(BaseOutputParser[bool]):
    """将LLM调用的输出解析为布尔值。"""

    true_val: str = "YES"
    """应该解析为True的字符串值。"""
    false_val: str = "NO"
    """应该解析为False的字符串值。"""

[docs]    def parse(self, text: str) -> bool:
        """将LLM调用的输出解析为布尔值。

参数：
    text：语言模型的输出

返回：
    布尔值
"""
        regexp = rf"\b({self.true_val}|{self.false_val})\b"

        truthy = {
            val.upper()
            for val in re.findall(regexp, text, flags=re.IGNORECASE | re.MULTILINE)
        }
        if self.true_val.upper() in truthy:
            if self.false_val.upper() in truthy:
                raise ValueError(
                    f"Ambiguous response. Both {self.true_val} and {self.false_val} "
                    f"in received: {text}."
                )
            return True
        elif self.false_val.upper() in truthy:
            if self.true_val.upper() in truthy:
                raise ValueError(
                    f"Ambiguous response. Both {self.true_val} and {self.false_val} "
                    f"in received: {text}."
                )
            return False
        raise ValueError(
            f"BooleanOutputParser expected output value to include either "
            f"{self.true_val} or {self.false_val}. Received {text}."
        )

    @property
    def _type(self) -> str:
        """Snake-case字符串标识符，用于输出解析器类型。"""
        return "boolean_output_parser"
Source code for langchain.output_parsers.boolean
