timer.py

from threading import _Timer

class Timer(_Timer):

    def __init__(self, interval, handler, repeats=0, args=[], kwargs={}):
        _Timer.__init__(self, interval, self.__invoke, args, kwargs)

        self.handler = handler
        self.repeats = repeats

        self.repeatCount = 0
        self.running = False
        self.started = False

    def __invoke(self, args=[], kwargs={}):
        if not self.running:
            return
        self.handler(*args, **kwargs)
        self.repeatCount += 1

        self.running = False
        self.__run()

    def __run(self):
        if self.repeats == 0 or \
           self.repeatCount < self.repeats and not self.running:

            self.running = True
            self.run()

        elif self.repeatCount >= self.repeats:
            self.repeatCount = 0

    
    def start(self):
        if not self.started:
            self.running = True
            self.started = True
            _Timer.start(self)
        else:
            self.__run()

    def stop(self):
        self.canncel()
        self.running = False
    
    def reset(self):
        self.repeatCount = 0
        self.stop()

    def restart(self):
        self.reset()
        self.start()

#--- just test ---

def say():
    print 'hello world'

if __name__ == '__main__':
    t = Timer(2, say, 3);
    t.start()