Why does Python raise ModuleNotFoundError from cron but not manually?

[Jeffrey60]

I’ve been getting a weird error in my Python script where it says a module is not found, but only when I run it from a cron job. The import works fine when I execute it manually from the terminal. I’m not sure if it’s a path issue with the cron environment or something else.

[Andrew_T]

That sounds like the scheduled task environment isn't loading your venv or PATH. Try using the full path to Python and the script.

[PenelopeA]

In my case the import failed in cron but not in terminal because PYTHONPATH wasn't set for the job.

[GraceAT]

I added a line to print sys.executable and the module search paths to a log, and it showed the env was different.

[Andrew_T]

I fixed it by calling /usr/bin/python3 /home/me/scripts/myscript.py, no venv; then I had to install dependencies system-wide.

[Benjamin_L]

One time I thought it was a module issue, but the CWD in cron was different and a relative import broke.

[AnthonyH]

Another angle is to run the script from the cron directory with a proper cd or set WORKING_DIR.

[Elizabeth.S]

Do you have a virtualenv and a shebang line in the script?