it's trying to import it from your code since that's what you're supposed to define. that's the task. define that thing. it's failing since you haven't defined it.

I get this error:
STDERR:
Traceback (most recent call last):
File "/workspace/default/tests.py", line 2, in
from solution import is_isogram
ImportError: cannot import name 'is_isogram' from 'solution' (/workspace/default/solution.py)

The import 'is_isogram' belongs to the test cases, not my code! Any thoughts?