Using the function perfect_shuffle(a_list) which takes as argument a list and returns the perfect shuffle of the list. The function should not modify the argument list.
Example:
In [1]: my_list = [1, 2, 3, 4, 5, 6]
In [2]: my_shuffled_list = perfect_shuffle(my_list)
In [3]: print(my_shuffled_list)
[1, 4, 2, 5, 3, 6]
In [4]: print(my_list)
[1, 2, 3, 4, 5, 6]