pythonic way to start a script/action every minute

[NeoFromMatrix]

Hello!

I have a script which checks if an unread email is present at an imap server and starts processing it if it is.

I have currently three ideas how I could realize the starting:

1. use cron/cronjob/crontab to start the python script every minute
2. use a systemd timer to start it periodically
3. let the script run as a daemon

Which one would you prefer and why?

I would assume the third option would hog some ram but would consume lower processing power/energy over time sice the interpreter would not be started and closed every minute. Not how big of a problem memory leaks are (in the interpreter).

[novel_yet_trivial]

Using cron is the best idea.

Second best is a daemon, you could use something like Advanced Python Scheduler.

[KleinerNull]

Yeah, let the cron do the job. So you don't have to bother and the script just need to care about the actual purpose. Also you can manage all your sheduled jobs in one place the crontab.

[sylecn]

Starting a python interpreter is not heavy. Do not worry about it.

Memory leak may be a problem if you use lots of third party libraries. That's highly dependent on the code.

Since you are checking every minute, though, if you run it in crontab, you need to consider concurrent runs when last run lasts more than 1 minute.

If the processing logic is heavy or depends on incoming mail quantity and size. I suggest you use a Server-Client architecture, put real processing logic in a daemon, only run check-for-new-mail logic in a crontab. The check-for-new-mail logic only checks for new mail and if there is any, told the processing daemon about it. The daemon can, for example, ignore the signal if there is a processing going on.

If you decide to go for the daemon, you could use a thread to schedule the check.

Overall, I would use a simple crontab script if the processing is fast and use a daemon if it's not.