class cat:
    def __init__(self, name, age):
        self.__name = name
        self.__age = age
    def setname(self, name):
        self.__name = name
    def getname(self):
        return self.__name
    def setage(self, age):
        self.__age = age
    def getage(self):
        return self.__age
    missy = cat('missy', 3)
    lucky = cat('lucky', 5)
    print (missy.getname(), missy.getage())
    print (lucky.getname(), lucky.getage())

이렇게 작성했는데 cat이 정의 되지않았다고 나오는데 왜그런건가요?