python: object() 不带参数错误

Question

我正在尝试在 python2.7 中创建一个 enum 类。我的代码如下所示:

from enum import Enum

class Alarms(Enum):
    MOTION = "Motion", 0, False
    SOUND = "Sound", 1, False
    FIRE = "Fire", 2, False


    def __new__(cls, *args, **kwds):
        obj = object.__new__(cls)
        obj.value_ = args[0]
        return obj

    def __init__(self, name, modbusAddress, isActive):
        self.name = name
        self.modbusAddress = modbusAddress
        self.isActive = isActive

这是我收到的错误消息:

  File "/usr/lib/python2.7/dist-packages/enum/__init__.py", line 232, in __new__
    enum_member._value_ = member_type(*args)
TypeError: Error when calling the metaclass bases
    object() takes no parameters

Answer 1

您的__new__中有拼写错误:

obj.value_ = args[0]

应该是

obj._value_ = args[0]

(注意前导下划线)

如果您确实需要 value_ 属性，那么您需要同时设置这两个属性。