Some problem with score evaluation system

i submitted ‘’ Practice Programming Assignment: Python Basics with Numpy’’ and i got 88/100 and i don’t know why and i got this description and i don’t know how to fix it if it’s the reason of some score loss of my assignment.

this :

[ValidateApp | INFO] Validating ‘/home/jovyan/work/submitted/courseraLearner/W2A1/Python_Basics_with_Numpy.ipynb’
[ValidateApp | INFO] Executing notebook with kernel: python3
Tests failed on 1 cell(s)! These tests could be hidden. Please check your submission.

Hey @hmdsmit, this is because one function in the assignment passed the unit test, but failed the test of the grader. This could be because you might be using global variables or hardcoded values in the functions. which you shouldn’t be.