Source code for langchain.output_parsers.enum
from enum import Enum
from typing import Dict, List, Type
from langchain_core.exceptions import OutputParserException
from langchain_core.output_parsers import BaseOutputParser
from langchain_core.utils import pre_init
[docs]class EnumOutputParser(BaseOutputParser[Enum]):
"""Parse an output that is one of a set of values."""
enum: Type[Enum]
"""The enum to parse. Its values must be strings."""
@pre_init
def raise_deprecation(cls, values: Dict) -> Dict:
enum = values["enum"]
if not all(isinstance(e.value, str) for e in enum):
raise ValueError("Enum values must be strings")
return values
@property
def _valid_values(self) -> List[str]:
return [e.value for e in self.enum]
[docs] def parse(self, response: str) -> Enum:
try:
return self.enum(response.strip())
except ValueError:
raise OutputParserException(
f"Response '{response}' is not one of the "
f"expected values: {self._valid_values}"
)
@property
def OutputType(self) -> Type[Enum]:
return self.enum