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。

如果你正在使用终端(ssh或其他东西)，并且你想在退出终端后保持长时间的脚本工作，你可以尝试这样做:

屏幕

Apt-get安装屏幕

在里面创建一个虚拟终端(即abc): screen -dmS abc

现在我们连接到abc: screen -r abc

因此，现在我们可以运行python脚本:python keep_sending_mail .py

从现在开始，你可以直接关闭你的终端，但是，python脚本将继续运行而不是被关闭

因为这个keep_sending_mail .py的PID是虚拟屏幕的子进程，而不是 终端(ssh)

如果你想检查你的脚本运行状态，你可以再次使用screen -r abc

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。

首先，仔细研究邮件别名。邮件别名将在邮件系统内完成此任务，而无需您在守护进程或服务或任何类似的东西上瞎忙活。

您可以编写一个简单的脚本，每次将邮件消息发送到特定邮箱时，sendmail都会执行该脚本。

参见http://www.feep.net/sendmail/tutorial/intro/aliases.html

如果您真的想编写一个不必要的复杂服务器，您可以这样做。

nohup python myscript.py &

这就够了。您的脚本只是循环和休眠。

import time
def do_the_work():
    # one round of polling -- checking email, whatever.
while True:
    time.sleep( 600 ) # 10 min.
    try:
        do_the_work()
    except:
        pass

您还可以使用shell脚本使python脚本作为服务运行。首先创建一个shell脚本，像这样运行python脚本(scriptname任意名称)

#!/bin/sh
script='/home/.. full path to script'
/usr/bin/python $script &

现在在/etc/init.d/scriptname中创建一个文件

#! /bin/sh

PATH=/bin:/usr/bin:/sbin:/usr/sbin
DAEMON=/home/.. path to shell script scriptname created to run python script
PIDFILE=/var/run/scriptname.pid

test -x $DAEMON || exit 0

. /lib/lsb/init-functions

case "$1" in
  start)
     log_daemon_msg "Starting feedparser"
     start_daemon -p $PIDFILE $DAEMON
     log_end_msg $?
   ;;
  stop)
     log_daemon_msg "Stopping feedparser"
     killproc -p $PIDFILE $DAEMON
     PID=`ps x |grep feed | head -1 | awk '{print $1}'`
     kill -9 $PID       
     log_end_msg $?
   ;;
  force-reload|restart)
     $0 stop
     $0 start
   ;;
  status)
     status_of_proc -p $PIDFILE $DAEMON atd && exit 0 || exit $?
   ;;
 *)
   echo "Usage: /etc/init.d/atd {start|stop|restart|force-reload|status}"
   exit 1
  ;;
esac

exit 0

现在可以使用/etc/init.命令启动和停止python脚本D /scriptname start or stop。

您可以在脚本中或像这样在另一个脚本中作为子进程运行进程

subprocess.Popen(arguments, close_fds=True, stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL, stdin=subprocess.DEVNULL)

或者使用现成的工具

https://github.com/megashchik/d-handler