定义 属性方法的作用就是通过@property把一个方法变成一个静态属性
class Student(object): stu_num = 0 def init(self,name): self.name = name @property def fly(self): print("%s is flying..." % self.name) s = Student("Mjj") s.fly() 调用会出以下错误， 说NoneType is not callable, 因为fly此时已经变成一个静态属性了， 不是方法了， 想调用已经不需要加()号了，直接s.fly就可以了
Mjj is flying... Traceback (most recent call last): File "/day6_面向对象进阶/属性方法.py", line 14, in s.fly() TypeError: 'NoneType' object is not callable 正常调用 s.fly 输出 Mjj is flying... property应用场景 好吧，把一个方法变成静态属性有什么卵用呢？既然想要静态变量，那直接定义成一个静态变量不就得了么？well, 以后你会需到很多场景是不能简单通过 定义 静态属性来实现的， 比如 ，你想知道一个航班当前的状态，是到达了、延迟了、取消了、还是已经飞走了， 想知道这种状态你必须经历以下几步:
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连接航空公司API查询
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对查询结果进行解析
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返回结果给你的用户
因此这个status属性的值是一系列动作后才得到的结果，所以你每次调用时，其实它都要经过一系列的动作才返回你结果，但这些动作过程不需要用户关心， 用户只需要调用这个属性就可以，明白 了么？
class Flight(object): def init(self,name): self.flight_name = name def checking_status(self): print("connecting airline company api...... " ) print("checking flight %s status " % self.flight_name) return 1 @property def flight_status(self): status = self.checking_status() if status == 0 : print("flight got canceled...") elif status == 1 : print("flight is arrived...") elif status == 2: print("flight has departured already...") else: print("cannot confirm the flight status...,please check later") f = Flight("CA980") f.flight_status cool , 那现在我只能查询航班状态， 既然这个flight_status已经是个属性了， 那我能否给它赋值呢？试试吧
f = Flight("CA980") f.flight_status f.flight_status =3 输出， 说不能更改这个属性，我擦。。。。，怎么办怎么办。。。
Traceback (most recent call last): connecting airline company api...... File "/day6_面向对象进阶/属性方法.py", line 41, in f.flight_status =3 AttributeError: can't set attribute checking flight CA980 status flight is arrived... 当然可以改， 不过需要通过@proerty.setter装饰器再装饰一下，此时 你需要写一个新方法， 对这个flight_status进行更改。
class Flight(object): def init(self,name): self.flight_name = name def checking_status(self): print("connecting airline company api...... " ) print("checking flight %s status " % self.flight_name) return 1 @property def flight_status(self): status = self.checking_status() if status == 0 : print("flight got canceled...") elif status == 1 : print("flight is arrived...") elif status == 2: print("flight has departured already...") else: print("cannot confirm the flight status...,please check later") @flight_status.setter # 修改 def flight_status(self,status): status_dic = { 0 : "canceled", 1 : "arrived", 2 : "departured" } print("\033[31;1mHas changed the flight status to \033[0m",status_dic.get(status) ) f = Flight("CA980") f.flight_status f.flight_status = 1 输出
connecting airline company api……
checking flight CA980 status
flight is arrived…
Has changed the flight status to arrived
还可以删除
@flight_status.deleter #删除
def flight_status(self):
print("status got removed...")
f = Flight("CA980")
f.flight_status
f.flight_status = 1
del f.flight_status
