Python 继承与装饰

有人能为我解释一下为什么这会产生一个名称错误，其中类a找不到decorator\u warehouse变量，即使它位于其父类Mixin的内部

NameError: name 'decorator_warehouse' is not defined

此外，我如何才能获得所需的功能，即将decorator_仓库放在一个不同的类中，而不是包含我希望装饰的功能的类中

class DecoratorWarehouse(object):
    """Object hosts a large number of custom decorators"""
    def custom_decorator_A(self, func):
        def wrapper(*args, **kwargs):
            print "doing stuff before call"
            res = func(*args, **kwargs)
            print "doing stuff after call"
            return res
        return wrapper

class Mixin(object):
    decorator_warehouse = DecoratorWarehouse()


class A(Mixin):
    @decorator_warehouse.custom_decorator_A
    def doing_stuff(self):
        print "Doing some stuff"

a = A()

a.doing_stuff()

在这里找到了答案：

可能重复的

class A(Mixin):
    @Mixin.decorator_warehouse.custom_decorator_A
    def doing_stuff(self):
        print "Doing some stuff"