枚举解析器

本笔记本展示了如何使用枚举输出解析器

from langchain.output_parsers.enum import EnumOutputParser

API 参考：

EnumOutputParser 来自 langchain.output_parsers.enum

from enum import Enum

class Colors(Enum):
    RED = "red"
    GREEN = "green"
    BLUE = "blue"

parser = EnumOutputParser(enum=Colors)

parser.parse("red")

输出结果：

<Colors.RED: 'red'>

# 可以处理空格
parser.parse(" green")

输出结果：

<Colors.GREEN: 'green'>

# 可以处理换行符
parser.parse("blue\n")

输出结果：

<Colors.BLUE: 'blue'>

# 在适当的情况下会引发错误
parser.parse("yellow")

输出结果：

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)

File ~/workplace/langchain/langchain/output_parsers/enum.py:25, in EnumOutputParser.parse(self, response)
     24 try:
---> 25     return self.enum(response.strip())
     26 except ValueError:

File ~/.pyenv/versions/3.9.1/lib/python3.9/enum.py:315, in EnumMeta.__call__(cls, value, names, module, qualname, type, start)
    314 if names is None:  # simple value lookup
--> 315     return cls.__new__(cls, value)
    316 # otherwise, functional API: we're creating a new Enum type

File ~/.pyenv/versions/3.9.1/lib/python3.9/enum.py:611, in Enum.__new__(cls, value)
    610 if result is None and exc is None:
--> 611     raise ve_exc
    612 elif exc is None:

ValueError: 'yellow' 不是一个有效的 Colors

During handling of the above exception, another exception occurred:

OutputParserException                     Traceback (most recent call last)

Cell In[8], line 2
      1 # 在适当的情况下会引发错误
----> 2 parser.parse("yellow")

File ~/workplace/langchain/langchain/output_parsers/enum.py:27, in EnumOutputParser.parse(self, response)
     25     return self.enum(response.strip())
     26 except ValueError:
---> 27     raise OutputParserException(
     28         f"Response '{response}' 不是预期值之一：{self._valid_values}"
     29     )

OutputParserException: Response 'yellow' 不是预期值之一：['red', 'green', 'blue']

枚举解析器

API 参考：​

API 参考：