No module named ‘__main__.main_util’

That means you need to have a project imported somewhere in your current runtime environment or loaded first.

Given a list, write a ModuleNotFoundError: No module named ‘main.main_util’; ‘main‘ is not a package.

ModuleNotFoundError: No module named ‘main.main_util’; ‘main‘ is not a package simply remove the dot(.) for the relative import and do:

Exmaple

#Old code
from .main_util import DevnoteTestCase

#New code 
from main_util import DevnoteTestCase