Simple event dispatcher

trigger.py

class Event(object):
    
    def __init__(self):
        self.callables = {}
    
    def on(self, func, uid=None):
        if not callable(func):
            raise TypeError("callable required")
        if not uid:
            uid = str(hash(func))
        
        self.callables[uid] = func
    
    def off(self, func):
        if type(func) == str:
            del self.callables[func]
        else:
            del self.callables[str(hash(func))]
    
    def fire(self, *args, **kwargs):
        for key in self.callables:
            func = self.callables[key]
            yield func(*args, **kwargs)