python封装与继承

封装步骤：
1.属性私有化，---》__name
2.设置set和get方法，--->set_name(),get_name()
3.添加安全条件判断，---》参数类型判断，取值范围判断
"""


class Dog(object):
    def __init__(self, legnum):
        self.__legnum = legnum

    def set_legnum(self, legnum):
        if legnum < 0 or legnum > 4:
            print('无耻')
            return
        self.__legnum = legnum

    def get_legnum(self, str1):
        if str1 == 'ok':
            return self.__legnum
        else:
            print('答案不对，请重新输入')


wangcai = Dog(4)
print(wangcai._Dog__legnum)

"""
继承：子类继承父类的成员
子类可以直接调用父类中的属性和方法
"""


class Person(object):

    def __init__(self, name):
        print('第二个重载的构造方法')
        self.name = name
        self.age = 20
        pass

    def __add__(self, other):
        p = Person('')
        p.name = self.name + other.name
        return p

    def __mul__(self, other):
        p = Person('')
        p.name = self.name * other
        return p

    def __str__(self):
        return '{},{}'.format(self.name, self.age)

    def __len__(self):
        return len(self.name)


per = Person('jack')
per2 = Person('tom')
print(per+per2)
print((per.__mul__(2)))