你可以使用fork()将你的脚本从tty中分离出来，并让它继续运行，如下所示:

import os, sys
fpid = os.fork()
if fpid!=0:
  # Running as daemon now. PID is fpid
  sys.exit(0)

当然你还需要实现一个无限循环，比如

while 1:
  do_your_check()
  sleep(5)

希望这能让你开始。

你可以使用fork()将你的脚本从tty中分离出来，并让它继续运行，如下所示:

import os, sys
fpid = os.fork()
if fpid!=0:
  # Running as daemon now. PID is fpid
  sys.exit(0)

当然你还需要实现一个无限循环，比如

while 1:
  do_your_check()
  sleep(5)

希望这能让你开始。

在linux下使用$nohup命令如何?

我用它在Bluehost服务器上运行命令。

如果我错了，请指教。

cron is clearly a great choice for many purposes. However it doesn't create a service or daemon as you requested in the OP. cron just runs jobs periodically (meaning the job starts and stops), and no more often than once / minute. There are issues with cron -- for example, if a prior instance of your script is still running the next time the cron schedule comes around and launches a new instance, is that OK? cron doesn't handle dependencies; it just tries to start a job when the schedule says to.

如果您发现确实需要一个守护进程(一个永不停止运行的进程)，请查看一下监控器。它提供了一种简单的方法来包装普通的、非守护进程化的脚本或程序，并使其像守护进程一样运行。这比创建本地Python守护进程好得多。

一个简单且受支持的版本是Daemonize。

从Python包索引(PyPI)安装它:

$ pip install daemonize

然后用like:

...
import os, sys
from daemonize import Daemonize
...
def main()
      # your code here

if __name__ == '__main__':
        myname=os.path.basename(sys.argv[0])
        pidfile='/tmp/%s' % myname       # any name
        daemon = Daemonize(app=myname,pid=pidfile, action=main)
        daemon.start()

你有两个选择。

Make a proper cron job that calls your script. Cron is a common name for a GNU/Linux daemon that periodically launches scripts according to a schedule you set. You add your script into a crontab or place a symlink to it into a special directory and the daemon handles the job of launching it in the background. You can read more at Wikipedia. There is a variety of different cron daemons, but your GNU/Linux system should have it already installed. Use some kind of python approach (a library, for example) for your script to be able to daemonize itself. Yes, it will require a simple event loop (where your events are timer triggering, possibly, provided by sleep function).

我不建议你选择2。，因为您实际上是在重复cron功能。Linux系统范例是让多个简单工具交互并解决您的问题。除非有其他原因需要创建守护进程(除了定期触发之外)，否则选择其他方法。

此外，如果你使用daemonize进行循环并且发生了崩溃，那么没有人会在那之后检查邮件(正如Ivan Nevostruev在回答的评论中指出的那样)。而如果脚本作为cron作业添加，它将再次触发。