class Student(object):
def __init__(self, name, score):
self.name = name
self.score = score
def get_grade(self):
if not isinstance(self.score, int): raise ValueError('invalidate score!')
if self.score > 100 or self.score < 0:
raise ValueError('invalidate score! score value between "0" and "100".')
if self.score >= 80:
return 'A'
if self.score >= 60:
return 'B'
return 'C'
EddieLau_