class Student(object):

    def __init__(self,name,score):
        self.name=name
        self.score=score

    def print_score(self):
        print("%s: %s" % (self.name,self.score))

    def get_grade(self):
        if self.score >= 90:
            return "A"
        elif self.score >= 60:
            return "B"
        else:
            return "C"

bart=Student("Bart Simpson", 59)
lisa=Student("Lisa Simpson", 87)

print("bart.name=", bart.name)
print("bart.score=", bart.score)
bart.print_score()

print("grade of Bart:", bart.get_grade())
print("grade of Lisa:", lisa.get_grade())