yield.py

    def listen_event(self, event, *args, **kwargs):
        '''Fires an event.'''
        events = self.__events.get(event, {})
        for key in events:
            for val in events[key](*args, **kwargs):
              yield val

            
            
# example

emitter = EventEmitter()
def one_to_ten():
    for i in range(10):
        yield i
emitter.on('one_to_ten', one_to_ten, "key1")
emitter.on('one_to_ten', one_to_ten, "key2")

for i in emitter.listen_event("one_to_ten"):
    print(i)
    
# prints 1-10 twice?