Question

我的目标很简单：在特定时间启动periodicCallback。我试着到处寻找，但所有读取的例子都与当前时间的时间值有关，而与定义的时间无关。

我写了一个简单的例子。

import tornado.ioloop
import datetime
from datetime import date, time
from tornado.ioloop import IOLoop, PeriodicCallback

def startService():
    print("periodic thing")


def periodicCallback():
    periodic = PeriodicCallback(callback=startService,callback_time=5000)
    periodic.start()

if __name__ == "__main__":
    main_loop = IOLoop.instance()
    # I want to set a specific time
    starting_time = time(14, 30, 00)
    # After this time i would want to have the message "periodic thing" every callback_time
    (...)
    #my first test but i have error about deadline unsupported:
    IOLoop.current().add_timeout(starting_time, periodicCallback)
    main_loop.start()

感谢您的帮助

Answer 1

错误 - Unsupported deadline - 您之后看到的是因为add_timeout获取了datetime.timedelta个对象，而您提供了datetime.time个对象。

由于您希望在特定时间运行回调，因此可以计算到该时间的时间值。

import datetime

# see the current time
now = datetime.datetime.now()

# create a datetime object for your desired time
starting_time = datetime.datetime(year=2018, month=3, day=13, 
                                  hour=14, minute=30) 

# subtract `now` from `starting_time`
# to calculate timedelta
td = starting_time - now

main_loop.add_timeout(td, periodicCallback)

如果year或month或day与now时间相同，您也可以这样做：

starting_time = datetime.datetime(year=now.year, month=now.month, day=now.day, 
                                  hour=14, minute=30)

特定时间的python tornado periodicCallback

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