【小记】为枚举类型的枚举值添加label及其他属性

import inspect
import operator

from enum import Enum
from enum import EnumMeta
from functools import reduce


class BaseEnumMeta(EnumMeta):
    """ 枚举元类 """

    def __new__(mcs, name, bases, attrs):
        Label = mcs.get_meta("Label", attrs)
        Code = mcs.get_meta("Code", attrs)

        obj = super().__new__(mcs, name, bases, attrs)

        mcs.add_to_enum("label", obj, Label)
        mcs.add_to_enum("code", obj, Code)

        return obj

    @classmethod
    def get_meta(mcs, meta_name, attrs):
        """ 获取元数据 """
        meta = attrs.get(meta_name)
        if meta is None:
            return meta

        if inspect.isclass(meta):
            del attrs[meta_name]
            if hasattr(attrs, '_member_names'):
                attrs._member_names.remove(meta_name)
            return meta

        if inspect.isfunction(meta):
            del attrs[meta_name]
        return meta

    @classmethod
    def add_to_enum(mcs, name, obj, meta):
        """ 添加属性到枚举值上 """

        if inspect.isclass(meta):
            for item in obj:
                setattr(item, name, getattr(meta, item.name, None))

        if inspect.isfunction(meta):
            for item in obj:
                setattr(item, name, meta(item))

class BaseEnum(Enum, metaclass=BaseEnumMeta):

    @classmethod
    def has(cls, val):
        """ 判断一个值是否合法 """
        for item in cls:
            if val == item.code:
                return True

        return False

    @classmethod
    def from_code(cls, value):
        """ 从 Code 构建枚举值 """
        return [item for item in cls if item.code == value][0]


class BitFlagEnum(int, BaseEnum, metaclass=BaseEnumMeta):
    """ 标志位枚举基类 """

    @classmethod
    def bit_mask(cls, values):
        """ 位掩码 """
        return reduce(
            operator.or_,
            [item for item in cls for val in values if item.code == val],
            0
        )

    @classmethod
    def bit_unmask(cls, val):
        """ 解析位掩码 """
        return [item.code for item in cls if item & val]

class QPrivyFieldsFlag(BitFlagEnum):
    """用户字段标志位"""
    NAME = 1
    DOCUMENT = 2
    PHONE = 4
    EMAIL = 8

    class Label:
        NAME = "姓名"
        DOCUMENT = "证件类型·证件号"
        PHONE = "手机号"
        EMAIL = "邮箱"

    def Code(self):
        return self.name.lower()

class DocumentType(BaseEnum):
    """用户证件类型"""
    id_card = "01"
    pass_port = "02"
    org_code = "03"
    credit_code = "04"
    biz_license_code = "05"

    class Label:
        id_card = "身份证"
        pass_port = "护照"
        org_code = "组织机构代码"
        credit_code = "统一社会信用代码"
        biz_license_code = "营业执照注册号"

    def Code(self):
        return self.value

>> DocumentType.id_card
<DocumentType.id_card: '01'>

>> DocumentType.id_card.label
'身份证'

>> DocumentType.id_card.name
'id_card'

>> DocumentType.id_card.value
'01'