from threading import Timerclass MyTimer: def __init__(self): self._timer= None self._tm = None self._fn = None def _do_func(self): if self._fn:  self._fn()  self._do_start() def _do_start(self): self._timer = Timer(self._tm, self._do_func) self._timer.start() def start(self, tm, fn): self._fn = fn self._tm = tm self._do_start() def stop(self): try:  self._timer.cancel() except:  passdef hello(): from datetime import datetime print("hello world!", datetime.now())if __name__ == '__main__': mt = MyTimer() mt.start(2, hello) for i in range(10): import time time.sleep(1) mt.stop()