I get error when submit C3_W1_Assignment

When submit my assignment i get auto grader feed back
There was a problem compiling the code from your notebook. Details:
cannot assign to None (, line 351)
i don’t know where the problem
the code result same as expected output

Did you leave any “None” statements in the notebook? You cannot submit a partially completed notebook.

I am stuck here, Can some one please help me resolving this

@saswazs, this post is a duplicate, I replied to one of your other copies.