使用tornado实现定时执行任务

使用tornado实现轮询：

from tornado import web, ioloopimport datetimeclass MainHandler(web.RequestHandler):    def get(self):        self.write('Hello Tornado')def f2s():    print '2s ', datetime.datetime.now()def f5s():    print '5s ', datetime.datetime.now()if __name__ == '__main__':    application = web.Application([        (r'/', MainHandler),        ])    application.listen(8081)    ioloop.PeriodicCallback(f2s, 2000).start()  # start scheduler 每隔2s执行一次f2s    ioloop.PeriodicCallback(f5s, 5000).start()  # start scheduler    ioloop.IOLoop.instance().start()