class Student(object):

    #定义一个Student类，

    def __init__(self, name, score,age):

        self.name = name

        self.score = score

        self.age = age

    def print_score(self):

        #定义类方法,实例对象可调用

        return self.name,self.score

    def get_grade(self):

        if self.score >= 90:

            return 'A'

        elif self.score >= 60:

            return 'B'

        else:

            return 'C'

st1 = Student('lingyummu',67,25)

    #创建一个Student类对象st1

print(st1.name,st1.age,st1.score)

print(st1.print_score())

print(st1.get_grade())