Travel expenses (2 points)

A company wants to analyse the travel expenses of its employees and has obtained a list with the travel expenses for each of them. Each item of this list corresponds to the travel expenses of a month.

Write the modifier function expenses() that takes a list, te, as described, and modifies it in such a way that each element accumulates all the previous amounts, i. e., the first element does not change and the next ones will have the value: \(te_i = \sum_{n=0}^{i} te_n, 1\leq i<len(te)\). Moreover this list must include a new item at the end with the average of the expenses.

Save this function in file expenses.py.

Examples:

>>> le1 = [500, 250, 1000]
>>> expenses(le1)
>>> le1[:-1]
[500, 750, 1750]
>>> round(le1[-1], 1)
583.3

>>> le2 = [441, 244, 1023, 156, 1078, 367]
>>> expenses(le2)
>>> le2[:-1]
[441, 685, 1708, 1864, 2942, 3309]
>>> round(le2[-1], 1)
551.5

Note

More tests are provided in file test-expenses.txt.