为啥要有return false?有什么作用?

class Dog:
def init(self,name):
self.__name=name
self.__age=None
print(self.__name,"生成成功")

def set_age(self,age):
    if not isinstance(age,int):
        print("输入的年龄必须是数字")
        return False
    if age <=0:
        print("年龄必须大于0")
        return False
    self.__age=age
def play(self):
    print("汪汪汪!我今年",self.__age)

dog=Dog("旺财")
dog.set_age("hello")
dog.set_age(-2)
dog.set_age(18)
dog.play()

return False表示未成功实例化,因为输入参数不符合要求