** Need help in writing these excersices in python language.

(d) Do these Python exercises: (d.1a) Implement the function compute GPA that takes as input a list of strings representing letter grades and returns the grade point average (out of 4 with A-4, B-3, C-2, D-1, and F-o) computed from the list. Assume there are no plus or minus grades (d.1b) Implement a new function compute.GPAd that also computes a GPA from a list of grades. But where you (probably) used a series of if-statements the first time, this time you should use a dictionary (and no if-statements). Your dictionary should map each letter grade to the number of grade points it's worth, including plus and minus grades that are 0.3 points above and below the base letter grade. assert compute GPACC'A, 'C', A ', 'A', 'F 'D)2.5714285714285716 assert compute-GPAd(L'A', 'C', 'A', 'B', 'A', 'F', 'D'])-2.5714285714285716 (d.2) Implement the function unroll_2D_list that takes as input a two-dimensional table (a list containing lists) and returns the input as a single list containing, in order, all the elements on the original nested list. assert un rol 2D-list([[1, 3, 2], [3, 5, 1], [7, 5, 1], [3, 2], [9, 4]])