>>>class Student(object):
        def set_age(self,age):
            self.age = age

>>>from types import MethodType
>>>s = Student()
>>>s.set_age = MethodType(set_age,s)
>>>s.set_age(19)
>>>s.age
>>>19

>>>s1 = Student()
>>>s1.set_age(25)
>>>s1.age
>>>25

不报错啊！！！