python用线程封装的一个简单的定时器类，python定时器,from threadi

python用线程封装的一个简单的定时器类，python定时器,from threadi

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()