def reverse_list(l):
    index = 0
    while index < len(l) / 2:
        # We'll call the index of the item to swap with the right_index,
        # since it's the index into the right half of the list.

        # Because indices start at 0, the last item of the list is at
        # index len(l) - 1.
        right_index = len(l) - 1 - index

        # Swap the items at index and right_index.
        temp = l[index]  # store the value at l[index] before clobbering
        l[index] = l[right_index]
        l[right_index] = temp

        index = index + 1

test_list = [1, 3, 5, 7, 9, 11, 13, 15]
print( "The list before reversing:  " + str(test_list) )
reverse_list(test_list)
print( "The list after reversing:  " + str(test_list) )