Calculating A Class Avg From A File

For this function, I want the class average for each assignment. I get this error when I try to test my function. Can anyone please help me fix this? I want to go through the colum

Solution 1:

Create a 2d list ..... Read all the lines and then just do computation on the colomns you want output for ... Accessing the column is something like

#example in python console
>>> list = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
>>> new_list = [item[1] for item in list]
>>> new_list
[2, 5, 8]