day 21作业

2. 定义一个类：圆形，该类有半径，周长，面积等属性，将半径隐藏起来，将周长与面积开放

import math
class Circle:
    def __init__(self,r):
        self.__r = r

    def out_perimeter(self):
        perimeter = int(self.__r)*math.pi*2
        return perimeter

    def out_area(self):
        area = math.pi * int(self.__r)**2
        return area

3. 使用abc模块定义一个phone抽象类 并编写一个具体的实现类

import abc
class Phone(metaclass=abc.ABCMeta):
    @abc.abstractmethod
    def Play_Phone(self):
        pass
    @abc.abstractmethod
    def Photos(self):
        pass

class phone_son(Phone):
    def Play_Phone(self):
        print('Play_phone')

    def Photos(self):
        print('Photo')

phone = phone_son()
phone.Photos()