Python print 的时候出现<__main__.Observer object at 0x0224F3B0>

Question

class Observer(object): def __init__(self,subject): self.subject = subject self.weather = self.subject.weather self.subject.add_observer(self) def update(self,weather,temperature,tips): self.weather = weather self.temperature = temperature self.tips = tips self.display() def display(self): return ("今日天气：{} \n今日气温： {} \n今日建议：{}").format(self.weather,self.temperature,self.tips) class Weather(object): def __init__(self): self.observers = [] self.weather = "" self.temperature = "" self.tips = "" def add_observer(self,observer): self.observers.append(observer) def delete_observer(self,observer): if observer in self.observers: self.observers.remove(observer) def notify(self): for observer in self.observers: observer.update(self.weather,self.temperature,self.tips) def add_data(self,weather,temperature,tips): self.weather = weather self.temperature = temperature self.tips = tips self.notify() if name=='main': subject= Weather() observer = Observer(subject) subject.add_data('多云转阴','10~23℃','请注意别感冒！') subject.add_observer('张三') subject.add_observer('李四') subject.add_observer('Ben') def Print(): ox = subject.observers for o in ox: weather_data = observer.display() print("{}你好，以下是今日的天气播报：\n{}\n").format(o,weather_data) Print() 初学Python，在做观察者模式的时候发现print会打印出多余的东西 <main.Observer object at 0x0224F3B0>你好，以下是今日的天气播报： 今日天气：多云转阴 今日气温： 10~23℃ 今日建议：请注意别感冒！ 请问这是什么原因，以及解决之道

Answer 1

在Class Observer的init函数中，self.subject.add_observer(self)语句将Weather的实例对象append到Weather的observers list里面了。