Pydantic json 值在自定義枚舉上為空

Question

我正在使用 Pydantic 我希望我的枚舉也有文檔字符串。

當我使用enum.Enum CookingModel工作正常。

import enum
from pydantic import BaseModel, ValidationError

class DocEnum(enum.Enum):
    """Enum with docstrings support"""

    def __new__(cls, value, doc=None):
        """add docstring to the member of Enum if exists

        Args:
            value: Enum member value
            doc: Enum member docstring, None if not exists
        """
        obj = str.__new__(cls)
        obj._value_ = value
        if doc:
            obj.__doc__ = doc
        return obj


class FruitEnum(str, enum.Enum):
    pear = 'pear'
    banana = 'banana'

class CookingModel(BaseModel):
    fruit: FruitEnum

a = CookingModel(fruit='banana')

a.json()

將返回： {"fruit": "banana"}

但是當我將enum.Enum更改為DocEnum時（這樣我就可以獲得文檔字符串）。

class FruitEnum(str, DocEnum):
    pear = 'pear'
    banana = 'banana'

它將返回： {"fruit": ""}

我該如何解決？

Answer 1

將value作為第二個參數傳遞給str.__new__解決問題。

import enum
from pydantic import BaseModel, ValidationError

class DocEnum(enum.Enum):
    """Enum with docstrings support"""

    def __new__(cls, value, doc=None):
        """add docstring to the member of Enum if exists

        Args:
            value: Enum member value
            doc: Enum member docstring, None if not exists
        """
        obj = str.__new__(cls, value)
        obj._value_ = value
        if doc:
            obj.__doc__ = doc
        return obj


class FruitEnum(str, DocEnum):
    pear = 'pear', 'it's pear docstring'
    banana = 'banana'