如果不将score的属性设置成隐私的，为啥就会报错
class Student(object):
def __init__(self, name, score):
self.name = name
self.score = score#这里以及后面会用到score的地方都不设置成隐私，会报错
@property
def score(self):
return self.score
@score.setter
def score(self, score):
if score < 0 or score > 100:
raise ValueError('invalid score')
self.score = score
@property
def grade(self):
if self.score < 60:
return 'C'
if self.score < 80:
return 'B'
return 'A'
s = Student('Bob', 59)
print s.grade
s.score = 60
print s.grade
s.score = 99
print s.grade
你快看~~
