Python-为什么不能删除继承对象的属性？

Question

Why can't attributes of inherited object be deleted?

class A(object):
    def delete(self):
        pass
    def dont_delete(self):
        pass


class B(A):
    pass

del A.delete
del B.dont_delete
AttributeError: dont_delete

Answer 1

dont_delete is not copied over to B ; you can only delete direct attributes from objects.

Python looks up attributes on instances and classes by delegating down the chain of inheritance, not by copying attributes across to sub-classes. As such there is nothing to delete from a subclass either.

You should not try and 'uninherit'; when are using A as a base class, you are effectively stating that B is the same thing as A , only more specialised. That process only ever should add attributes, not remove. Design your classes accordingly; use a mixin base class for attributes and methods that should not always be inherited, for example.