python定时器代码一例

class SLTimer(multiprocessing.Process):
    #from datetime import datetime
    #import time
    def __init__(self, target=None, args=(), kwargs={},date=None,time=None):
        '''
        @param date 1900-01-01
        @param time 00:00:00
        '''
        super(SLTimer,self).__init__(target=target,args=args,kwargs=kwargs)
        _date = ''
        if date is None:
            _date = datetime.now().__str__()[:10]
        else :
            _date = date
        _time = ''
        if time is None:
            _time = datetime.now().__str__()[11:19]
        else:
            _time = time
        self.__runtime = '%s %s' % (_date,_time)
    def run(self):
        timeLen = len('1900-00-00 00:00:00')
        while True:
            now = datetime.now().__str__()[:timeLen]
            if now>=self.__runtime:
                break
            print 'sleeping... %s' % now
            time.sleep(1.0)
        super(SLTimer,self).run()

def show1():
    from datetime import datetime
    print 'hello,current time:%s' % datetime.now().__str__()
def t23():
    from  stock.task import SLTimer
    timer = SLTimer(show1, time='16:31:50')
    timer.start()