write python script that is executed every 5 minutes

Question

I need to write a python script that autostarts on boot and is executed every 5 minutes on a raspberry pi. How can this be done? in particular, how can I avoid having a script locking up the cpu running a infine loop waiting for the 5 minutes to be over?

Remake

Use cron, but gevent will also be able to do the task nicely or sleep – Batting

Answer 1

You can easily use cron for this task (schedule to run Python script). ;)

How to setup cron

I suppose that you have cron installed already; if not, then install some (vixie-cron for an example).

Create a new file /etc/cron.d/<any-name>.cron with the following content:

# run script every 5 minutes
*/5 * * * *   myuser  python /path/to/script.py

# run script after system (re)boot
@reboot       myuser  python /path/to/script.py

where myuser is the user to run the script (it shouldn’t be root if possible, for security reasons). If this doesn’t work, then try to append the content to /etc/crontab instead.

You might want to redirect stdout/stderr of the script to file, so you can check if everything works fine. This is same as in shell, just add something like >>/var/log/<any-name>-info.log 2>>/var/log/<any-name>-error.log after the script path.

Morelock

thanks! do you have an example on how to set it up on raspbian? – Remake

It depends on OS you have on your Raspberry, it’s irrelevant that it’s a Raspberry, not PC. However it’s basically the same on all Linux distros. I’ve updated my answer, hope it helps. – Morelock

Ah, Raspbian is actually a distro, not some short for Raspberry Pi. :) – Morelock

thanks! root is disabled anyway on raspbian.. :) what if i need to make a reboot through my script? it wont work with a different user.. – Remake

Then you just run sudo reboot from the script…? – Morelock

great thanks! do i need to "start" the cron somehow? i created the file but its not doing anything.. also, i did not understand your sentence about /etc/crontab – Remake

Of course, cron is a daemon, you should add it to runlevel to be started automatically after boot. – Morelock

ive been googeling till now but cant seem to find how to add the daemon to autostart.. cant even find the name of the daemon... – Remake

Answer 2

Use schedule

• wrap the scrip in a function

import schedule 
import time 


def func():
    print("this is python")

schedule.every(5).minutes.do(func)

while True:
    schedule.run_pending()
    time.sleep(1)

Curtin

Answer 3

You can use time.sleep

count = -1
while(not abort):
    count = (count+1) % 100
    if count == 0:
        print('hello world!')
    time.sleep(3)

Masse

Answer 4

I am considering your code takes less than 5 minutes, but the execution time for each run is not constant.

import time

while True:
  t= time.time()

  # your code goes here
................
........
  
  t= time.time()-t
  time.sleep(300-t)

Swaddle