python 动态给实例添加属性和方法并使用__slots__

from types import MethodType#创建一个空类class Person(object):    __slots__ = ("name", "age", "speak")per = Person()#动态添加属性，这体现了动态语言的特点(灵活)per.name = "tom"print(per.name)#动态添加方法‘‘‘def say(self):    print("my name is " + self.name)per.speak = sayper.speak(per)‘‘‘def say(self):    print("my name is " + self.name)per.speak = MethodType(say, per)per.speak()#思考：如果我们想要限制实例的属性怎么办？#比如，只允许给对象添加name,age,height,weight属性#解决：定义类的时候，定义一个特殊的属性(__slots__)，可以限制动态添加的属性per.height = 170print(per.height)