子类可以继承父类的公有成员，但是不可继承私有成员。
若在派生类中调用基类的方法，则super（teacher，self）.__init__(name,age,sex),或者Person.__init__(self,name,age,sex).
class Person(object): def __init__(self,name = '',age = 10,sex = 'man'): self.setName(name) self.setAge(age) self.setSex(sex) def setName(self,name): if not isinstance(name,str): print 'name must be string' return self.__name = name def setAge(self,age): if not isinstance(age,int): print' age must be integer' return self.__age = age def setSex(self,sex): if sex != 'man' and sex != 'woman': print 'sex must be man or women' return self.__sex = sex def show(self): print 'name:',self.__name print 'age:',self.__age print 'sex:',self.__sex >>> class Teacher(Person): def __init__(self,name = '',age = 30,sex = 'man',job= 'tutor'): Person.__init__(self,name,age,sex) self.setJob(job) def setJob(self,job): if not isinstance(job,str): print 'job must be string' return self.__job = job def show(self): Person.show(self) print'job:',self.__job >>> xiaoming = Person('xiaoming',30,'man') >>> xiaoming.show() name: xiaoming age: 30 sex: man >>> xiaohong = Teacher('xiaohong',40,'woman','math teacher') >>> xiaohong.show() name: xiaohong age: 40 sex: woman job: math teacher
