Sort students

Created by Antoine Mazières

Instructions

This is a triple exercise, it's an introduction to sorting lists in Python.

Exercise 1

Write a function `sort_a_list` that takes a list as argument and return the list sorted in the descending order, such as:

``````In [1]: from solution import sort_a_list

In [2]: l = [1, 3, 2, 4, 6, 5, 9, 7]

In [3]: sort_a_list(l)
Out[3]: [9, 7, 6, 5, 4, 3, 2, 1]
``````

Beware, I'll test it with other types, not only integers! But always with list of elements of the same type.

Exercise 2

Given a list where each element is a list of a mark, and a student name, such as:

``````[[37, 'Jeanette Wafer'], [6, 'Joshua Tran'], [85, 'Susan Maddox']]
``````

Write a function `sort_by_mark` that take as argument a similar list and returns it sorted by mark in the descending order. Such as:

``````In [1]: from solution import sort_by_mark

In [4]: my_class = [[6, 'Joshua Tran'], [37, 'Jeanette Wafer'], [85, 'Susan Maddox'], [84, 'Joseph Pedersen'], [12, 'Bonnie Torres'], [36, 'John Freeman'], [27, 'Betty Askins'], [22, 'Mark Osbourne'], [42, 'Lidia Robel']]

In [5]: sort_by_mark(my_class)
Out[5]:
[84, 'Joseph Pedersen'],
[42, 'Lidia Robel'],
[37, 'Jeanette Wafer'],
[36, 'John Freeman'],
[22, 'Mark Osbourne'],
[12, 'Bonnie Torres'],
[6, 'Joshua Tran']]
``````

Exercise 3

Write a function `sort_by_name` that take as argument a similar list and returns it sorted by name in the ascending order. Such as:

``````In [1]: from solution import sort_by_name

In [6]: sort_by_name(my_class)
Out[6]:
[12, 'Bonnie Torres'],
[37, 'Jeanette Wafer'],
[36, 'John Freeman'],
[84, 'Joseph Pedersen'],
[6, 'Joshua Tran'],
[42, 'Lidia Robel'],
[22, 'Mark Osbourne'],
Have a look at `itemgetter`.