class student(object): #新式類
  def __init__(self,id): 
    self.__id=id 
  @property #讀 
  def score(self): 
    return self._score 
  @score.setter #寫 
  def score(self,value): 
    if not isinstance(value,int): 
      raise ValueError('score must be an integer!')  
    if value<0 or value>100: 
      raise ValueError('score must between 0 and 100')  
    self._score=value 
  @property #讀(只能讀，不能寫) 
  def get_id(self): 
    return self.__id 
 
s=student('123456') 
s.score=60 #寫 
print s.score #讀 
#s.score=-2 #ValueError: score must between 0 and 100 
#s.score=32.6 #ValueError: score must be an integer! 
s.score=100 #寫 
print s.score #讀 
print s.get_id #讀（只能讀，不可寫）
#s.get_id=456 #只能讀，不可寫:AttributeError: can't set attribute

class A(object):#要求繼承object
  def __init__(self):
    self.__name=None
  
  #下面開始定義屬性，3個函數(shù)的名字要一樣！
  @property #讀
  def name(self):
    return self.__name
  @name.setter #寫
  def name(self,value):
    self.__name=value
  @name.deleter #刪除
  def name(self):
    del self.__name
  
a=A()
print a.name #讀
a.name='python' #寫
print a.name #讀
del a.name #刪除
#print a.name # a.name已經(jīng)被刪除 AttributeError: 'A' object has no attribute '_A__name'