python 类的继承与重载

>>> class human:    __age=0    __sex=''    __height=0    __weight=0    name=''    def __init__(self,age,sex,height,weight):        self.__age=age        self.__sex=sex        self.__height=height        self.__weight=weight    def setname(self,name):        self.name=name    def show(self):        print(self.name)        print(self.__age)        print(self.__sex)        print(self.__height)        print(self.__weight)>>> class student(human):#通过继承human类生成student类    __classes=0    __grade=0    __num=0    def __init__(self,classes,grade,num,age,sex,height,weight):#重载        self.__classes=classes        self.__grade=grade        self.__num=num        human.__init__(self,age,sex,height,weight)#调用human类的__init__方法，初始化huamn类的属性，重载huamn类后又使用类的该方法，则用“父类.方法名”的方式调用    def show(self):#重载show()方法        human.show(self)#调用huamnn类的show方法        print(self.__classes)        print(self.__grade)        print(self.__num)>>> a=student(12,3,20070305,19,'male',175,65)#实例化生成a对象>>> a.setname('tom')#调用setname方法>>> a.show()#调用show方法，即用重载后的show方法输出属性tom19male1756512320070305