Mooc Python 2022 (part 1) 6_14. Comments on completed assignment not clear. Discord help not available.

[syamalsengupta]

I completed exercise 6_14 with output totally matching with output shown in the exercise. TMC is showing that my program is 50% correct with the following comments.
PASS:
Course Grading Part4Test:test_1works_with_files_1
FAIL: Course Grading Part4Test:test_2_works_with_files2
list index out of range

As it is not clear from the comments where I went wrong, I tried to connect Discord but their authorization window was not available. Under the circumstances, please help me understand my mistakes. I can put up my code in paste bin but then how do I get your advice.
Thanks.
course_grading_part_4.txt