Crontab not executing a Python script?

Question

My python script is not running under my crontab.

I have placed this in the python script at the top:

#!/usr/bin/python

I hav

Answer 1

Try to put in your crontab:

* * * * * python /path/to/your/script.py

rather than

* * * * * /path/to/your/script.py

Also the shebang line is #!/usr/bin/env python in some environments. env is an executable, and you have to know where it lives with "$ which env".

Answer 2

What happens when you type

/home/me/project/myscript.py into the shell?

Can you explicitly use /usr/bin/python in your crontbb command?

Can you either use an absolute path to your test.db or cd to the correct directory then execute your python script?

This is helpful to have debug statements in your python and log some data. Crontab can be very tricky to debug.

Answer 3

There are a lot of half answers across the internet so I thought I would capture this to save someone else some time.

First, cronjob does a poor job of telling you where this is failing. I recommend sending stderr output to a log file like this:

Crontab Command:

# m h  dom mon dow   command
* * * * * /path/to/your_file.sh >> out.txt  2>&1

As this is likely running the command as user, check home directory for the log file. Note this script runs every minute which is good for debugging.

The next issue is you probably have a path problem... as script likely is trying to execute from your home directory. This script sets the current directory, echos it to file, and then runs your program.

Try this :

Script File

#!/bin/sh
cd "$(dirname "$0")";
CWD="$(pwd)"
echo $CWD
python your_python_file.py

Hope this saves someone else some debugging time!!!

Answer 4

Typically, crontab problems like this are caused by the PATH environment variable being more restrictive/different than what your normal user's PATH environment is. Since your shell uses the PATH environment to find the executable (e.g. /usr/bin/python is found in /usr/bin when you type "python" at a shell prompt), when the PATH is missing common locations, like /usr/bin or /usr/sbin, your cron job will fail. This has bit me many times. The simple fix is just to explicitly set the PATH yourself near the top of your crontab file, before any commands that need it. So, just edit the crontab as usual and add something like this near the top (if your binary is not in one of the below paths, you'll need to add it after a colon):

PATH=/usr/local/bin:/usr/bin:/usr/local/sbin:/usr/sbin

Alternately, just use absolute paths to your binaries and scripts in crontab.

Answer 5

I was working on project that includes paramiko lib, when I run the Check_.py from cmdlin it works perfect but when I set the crontab it fails with error no module name paramiko.

So to make it short:
- there were two different python versions installed 3.7 and 2.4, so I used whreris python3 to locate the python path /usr/local/bin/python3.7m so replacing the python with the path will solve the issue.

Example

* * * * * cd /home/MKhair/hlthchk/BR/ && /usr/local/bin/python3.7m /home/MKhair/hlthchk/BR/Check_.py
* * * * * cd [ path-to-the-script-dir] && [path-to-python] [path-to-the-script]

Answer 6

If you are using anaconda for python then the path to use will be :

/home/username/anaconda3/bin/python test.py