在元类的情况下，我们如何访问继承的类属性

Question

即使var1 是ChildClass 类的成员，为什么我无法使用ChildClass.var1 访问var1

class MyType(type):
    def __getattribute__(self, name):
        print('attr lookup for %s' % str(name))
        return object.__getattribute__(self, name)
class BaseClass(object):
    __metaclass__ = MyType
    var1 = 5
class ChildClass(BaseClass):
    var2 = 6
print(ChildClass.var2) #works
print(ChildClass.var1) #fails

我收到以下错误

AttributeError: 'MyType' object has no attribute 'var1'

谢谢

Answer 1

由于MyType 是type，请使用type.__getattribute__ 而不是object.__getattribute__：

class MyType(type):
    def __getattribute__(self, name):
        print('attr lookup for %s' % str(name))
        return type.__getattribute__(self, name)