#继承
#重载，对继承过来的特征重新定义
#父类，基类
#子类，派生类

#继承：单继承-继承一个父类，多继承-继承多个父类
class father():
    def speak(self):
        print("i can speak")
#单继承
class son(father):
    pass
s=son()
s.speak()

class mother():
    def write(self):
        print("i can write")
#多继承,并且有自己的能力
class daughter(father,mother):
    def listen(self):
        print("i can listen")
d=daughter()
d.speak()
d.write()
d.listen()

#重写，重载
class son2(father):
    def speak(self):
        print("i can speak 2!")
s=son2()
s.speak()