How to run a python file using cron jobs

Question

Hi I have created a python file for example as file_example.py

The file will output the sensex value

Suppose the path of the file on linux system is /Desktop/downloads/file_example.py

and I normally will run the file like python file_example.py

But I want to set a cron job to run the python file every 2 min which is located at the above path

Can anyone please let me know how to do this

Edited Code:

I had edited the code and created a bash script with the name test.sh as indicated below

#!/bin/bash 
cd /Desktop/downloads/file_example.py
python file_example.py 2>log.txt

When I run the above file, the following error is displayed:

sh-4.2$ python test.sh
  File "test.sh", line 3
    python test.py 2>log.txt 
              ^
SyntaxError: invalid syntax

What does it do when you add your call to the crontab? What isn't working? — John3136, Aug 02 '12 at 09:48
@John3136: crontab: installing new crontab "/tmp/crontab.TdDFOh":1: bad minute errors in crontab file, can't install. Do you want to retry the same edit? — Shiva Krishna Bavandla, Aug 02 '12 at 10:46
Its displaying the above error when i tried to do this in cron tab /2 * * * * /Desktop/downloads/file_example.py — Shiva Krishna Bavandla, Aug 02 '12 at 10:47

score 60 · Answer 1 · edited Jan 24 '16 at 17:35

60

Assuming you are using a unix OS, you would do the following.

edit the crontab file using the command

crontab -e

add a line that resembles the one below

*/2 * * * * /Desktop/downloads/file_example.py

this can be used to run other scripts simply use the path to the script needed i.e.

*/2 * * * * /path/to/script/to/run.sh

An explanation of the timing is below (add a star and slash before number to run every n timesteps, in this case every 2 minutes)

* * * * * command to be executed
- - - - -
| | | | |
| | | | ----- Day of week (0 - 7) (Sunday=0 or 7)
| | | ------- Month (1 - 12)
| | --------- Day of month (1 - 31)
| ----------- Hour (0 - 23)
------------- Minute (0 - 59)

edited Jan 24 '16 at 17:35

Community

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answered Aug 02 '12 at 09:57

olly_uk

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The above code is useful , actually some times i have found that creating bash scripts(with .sh extension) and running those, can i know about this concept and both differs or same – Shiva Krishna Bavandla Aug 02 '12 at 10:02
you can run them exactly teh same way as long as the shebang line, e.g.#!/usr/bin/sh is included in the file – olly_uk Aug 02 '12 at 10:04
yes actually i had seen some paths in the file so confused , in bash command need to give the path of the file which is to be run ? – Shiva Krishna Bavandla Aug 02 '12 at 10:07
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look here http://en.wikipedia.org/wiki/Shebang_%28Unix%29 for explanation of shebang lines – olly_uk Aug 02 '12 at 10:09
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Thank you very much generally we will run the file using "python" command but here in the above example directly the path is given without command whether it automatically takes that command? – Shiva Krishna Bavandla Aug 02 '12 at 10:11
I had written a bash script but thats not working as u can observe above – Shiva Krishna Bavandla Aug 02 '12 at 10:37
i would create new question for a bash syntax error as this question is about use of crontab, and is resolved? – olly_uk Aug 02 '12 at 10:46
oh you want me to create another question for bash script ? – Shiva Krishna Bavandla Aug 02 '12 at 10:48
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don't you need to write python just before the python script to execute it? – Samadi Salahedine Jul 13 '18 at 08:57

score 39 · Answer 2 · answered Nov 12 '14 at 21:59

39

You can use python-crontab module.

https://pypi.python.org/pypi/python-crontab

To create a new cron job is as simple as follows:

from crontab import CronTab
#init cron
cron   = CronTab()

#add new cron job
job  = cron.new(command='/usr/bin/echo')

#job settings
job.hour.every(4)

answered Nov 12 '14 at 21:59

Guray Celik

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I don't know how come nobody happened to mention this till now. But one needs to add `cron.write()` to this code to actually make it work. I found this from here - http://stackabuse.com/scheduling-jobs-with-python-crontab/ – akki Jun 21 '18 at 06:11
@Guray Celik I am also using same module my cronjobs process are running but it doesnot executing code.I tried with somany script even like printing – Narender Reddy Feb 28 '19 at 05:38

How to run a python file using cron jobs

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