如何用Python创建后台线程运行schedule定时任务并配置参数

问题根源 #

你代码没有生效的核心原因是主线程只等待了10秒就调用stop_run_continuously.set()终止了后台调度线程，程序直接退出了，根本等不到17:00的执行时间点。

参数说明 #

• run_continuously的interval参数：这个是后台调度线程每次检查是否有到期任务的间隔时间，单位是秒。你是每天执行一次的任务，这个值设1~60秒都可以，设1秒的话最多误差1秒，设60秒最多误差1分钟，对按天执行的任务来说完全没影响，默认1秒就够用。
• 主线程里的time.sleep()：你原来写的10秒完全不足以支撑到任务执行时间，如果要让调度任务一直后台运行，就不能主动终止调度线程，需要让主线程一直保持运行状态。

修正后代码 #

import threading
import time
import schedule

def run_continuously(interval=1):
    """Continuously run, while executing pending jobs at each
    elapsed time interval.
    @return cease_continuous_run: threading. Event which can
    be set to cease continuous run. Please note that it is
    *intended behavior that run_continuously() does not run
    missed jobs*. For example, if you've registered a job that
    should run every minute and you set a continuous run
    interval of one hour then your job won't be run 60 times
    at each interval but only once.
    """
    cease_continuous_run = threading.Event()

    class ScheduleThread(threading.Thread):
        @classmethod
        def run(cls):
            while not cease_continuous_run.is_set():
                schedule.run_pending()
                time.sleep(interval)

    continuous_thread = ScheduleThread()
    # 设为守护线程，主线程退出时自动销毁
    continuous_thread.daemon = True
    continuous_thread.start()
    return cease_continuous_run

def background_job():
    exec(open('/Users/filename.py').read())

schedule.every().day.at("17:00").do(background_job)

# 启动后台线程
stop_run_continuously = run_continuously()

# 主线程一直阻塞不退出，保持后台调度运行
while True:
    time.sleep(3600)

额外注意事项 #

• 如果需要程序真正在系统后台脱离终端运行，Linux/macOS下可以直接用nohup python 你的脚本名.py &启动，Windows下可以把脚本打包成后台服务运行。
• 用exec执行外部py文件不是最优写法，你也可以把filename.py的逻辑封装成函数，直接导入调用更稳定。

内容的提问来源于stack exchange，提问作者Tcs106