C1_W3_Lab_Assignment_Ex3

Hi,
I’m getting an error when testing exercise 3 in lab assignment for course 1, week 3.
Very frustrating the lack of CLEAR error message - AssertionError might be relevant for those with lot of Python experience, but not for me (I know programming, but not Python).
SO, the output is ok, but the test fails.

Any suggestion?
Thank you!

Update: after a day of searching for the error source - I got it.
Problem solved.

how do you solve it?