请教大佬这两种写法有哪些不一样

我的答案：

class Student(object):

def __init__(self, name, score):

self.name = name

self.__score = score

self.__grade

@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 >= 80:

self.__grade = 'A'

elif self.__score >= 60:

self.__grade = 'B'

else:

self.__grade = 'C'

s = Student('Bob', 59)

print s.grade

s.score = 60

print s.grade

s.score = 99

print s.grade

慕课答案：

class Student(object):
def __init__(self, name, score):
self.name = name
self.__score = score
@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