xsubira

在我看来,这是一个愚蠢的变通办法。 所以才没有 TypeError 当 __slots__ 是空的,有一个空的 斯洛茨基 属性保留“奇怪的”python行为当分配给未在 斯洛茨基 .

所以,考虑一下 元类 :

class SlotBase(type):
    def __new__(cls,name,bases,dctn):
        if ('_slots_' in dctn) and not ('__slots__' in dctn):
            dctn['__slots__'] = []
        elif '__slots__' in dctn:
            for base in bases:
                if hasattr(base,'_slots_'):
                    dctn['__slots__'] += getattr(base,'_slots_')
        return super().__new__(cls,name,bases,dctn)

然后在基类上部署。

class A(metaclass=SlotBase):

    _slots_=['slot1'] #fake __slots__ attribute

    classPropertyA = 'Some silly value'

    def functA(self):
        print('I\'m functA')

class B(metaclass=SlotBase):

    _slots_=['slot2'] #fake __slots__ attribute

    classPropertyB = 'Some other silly value'

    def functB(self):
        print('I\'m functB')

class C(A,B):
    __slots__ = []

    classPropertyC = 'Just another silly value'

如果我们执行以下代码

c=C()
c.classPropertyC
c.classPropertyA
c.functA()
c.functB()
c.slot1='Slot exists then assignment is accepted'
c.slot3='Slot does not exists then assignment couldn\'t be accepted'

这将产生以下输出

Just another silly value
Some silly value
I'm functA
I'm functB
Traceback (most recent call last):
  File "/tmp/slots.py", line 41, in <module>
    c.slot3='Slot does not exists then assignment couldn\'t be accepted'
AttributeError: 'C' object has no attribute 'slot3'