python事件驱动模型的代码详解编程语言

__author__ = 'Administrator' 
#/usr/env/bin python 
  
''' 
  this is document 
''' 
class Event(object): 
    ''' 
      事件初始化的一个方式 
    ''' 
    def __init__(self,event_type,data=None): 
        self._type = event_type 
        self._data = data 
  
    @property 
    def type(self): 
        return self._type 
  
    @property 
    def data(self): 
        return self._data 
  
class EventDispatcher(object): 
     """ 
    event分发类 监听和分发event事件 
    """ 
     def __init__(self): 
         #初始化事件 
         self._events = dict() 
  
     def __del__(self): 
         self._events = None 
  
     def has_listener(self,event_type,listener): 
        if event_type in self._events.keys(): 
            return listener in self._events[event_type] 
        else: 
            return False 
  
     def dispatch_event(self,event): 
          """ 
        Dispatch an instance of Event class 
        """ 
        # 分发event到所有关联的listener 
          if event.type in self._events.keys(): 
              listeners = self._events[event.type] 
  
              for listener in listeners: 
                  listener(event) 
  
     def add_event_listener(self,event_type,listener): 
         #给某种事件类型添加listner 
         if not self.has_listener(event_type,listener): 
             listeners = self._events.get(event_type,[]) 
             listeners.append(listener) 
             self._events[event_type] = listeners 
  
     def remove_event_listener(self,event_type,listener): 
         if self.has_listener(event_type,listener): 
             listeners = self._events[event_type] 
             if len(listeners) == 1: 
                 del self._events[event_type] 
             else: 
                 listeners.remove(listener) 
                 self._events[event_type] = listeners 
  
class MyEvent(Event): 
    ASK = "askMyEvent" 
    RESPOND = "respondMyEvent" 
  
class WhoAsk(object): 
    def __init__(self,event_dispatcher): 
        self.event_dispatcher = event_dispatcher 
        self.event_dispatcher.add_event_listener( 
            MyEvent.RESPOND,self.on_answer_event 
        ) 
    def ask(self): 
        print("who are listener to me?") 
        self.event_dispatcher.dispatch_event(MyEvent(MyEvent.ASK,self)) 
  
    def on_answer_event(self,event): 
        print("receive event %s",event.data) 
  
class WhoRespond(object): 
   def __init__(self,event_dispatcher): 
       self.event_dispatcher = event_dispatcher 
       self.event_dispatcher.add_event_listener(MyEvent.ASK,self.on_ask_event) 
  
   def on_ask_event(self,event): 
       self.event_dispatcher.dispatch_event(MyEvent(MyEvent.RESPOND,self)) 
  
  
dispatcher = EventDispatcher() 
who_ask = WhoAsk( dispatcher ) 
who_responde1 = WhoRespond( dispatcher ) 
who_responde2 = WhoRespond( dispatcher ) 
  
# WhoAsk ask 
who_ask.ask()

使用事件驱动的方式写代码也不是一天两天了，今天突然发现这玩意居然有个理论在支撑这个。瞬间感到自己学的都是一点点皮毛而己。

python的事件模型的优势是，可以直接将某个方法放入事件中，这个好象要比java先进一点。