How do I reverse a sublist in a list in place?

Question

I\'m supposed to create a function, which input is a list and two numbers, the function reverses the sublist which its place is indicated by the two numbers. for example this is

Answer 1

I have two ways for in-place reversal, the simple way is to loop through the list half-way, swapping the elements with the respective mirror-elements. By mirror-element I mean (first, last), (2nd, 2nd-last), (3rd, 3rd-last), etc.

def reverse_list(A):
    for i in range(len(A) // 2): # half-way
        A[i], A[len(A) - i - 1] = A[len(A) - i - 1], A[i] #swap
    return A

The other way is similar to the above but using recursion as opposed to a "loop":

def reverse_list(A):
    def rev(A, start, stop):
        A[start], A[stop] = A[stop], A[start] # swap
        if stop - start > 1: # until halfway
            rev(A, start + 1, stop - 1)
        return A

    return rev(A, 0, len(A) - 1)