Reversing lists partially by reversing does not update the list

I am trying to work through the following problem:

Given an array, rotate the array to the right by k steps, where k is non-negative.

Example 1:

Input: nums = [1,2,3,4,5,6,7], k = 3
Output: [5,6,7,1,2,3,4]
Explanation:
rotate 1 steps to the right: [7,1,2,3,4,5,6]
rotate 2 steps to the right: [6,7,1,2,3,4,5]
rotate 3 steps to the right: [5,6,7,1,2,3,4]
Example 2:

Input: nums = [-1,-100,3,99], k = 2
Output: [3,99,-1,-100]
Explanation: 
rotate 1 steps to the right: [99,-1,-100,3]
rotate 2 steps to the right: [3,99,-1,-100]

I am trying to solve this problem by reversing the list, then reversing the first k elements of the list and then reversing the remainder of the list. Like this:

class Solution:
    def rotate(self, nums: List[int], k: int) -> None:
        """
        Do not return anything, modify nums in-place instead.
        """
        nums = nums[::-1]
        print('1st reverse', nums)
        nums[:k] = nums[:k][::-1]
        print('2nd reverse', nums)
        nums[k:] = nums[k:][::-1]
        print('final reverse', nums)

But this is my output. The list nums stays the same:

Your input
[1,2,3,4,5,6,7]
3

stdout
1st reverse [7, 6, 5, 4, 3, 2, 1]
2nd reverse [5, 6, 7, 4, 3, 2, 1]
final reverse [5, 6, 7, 1, 2, 3, 4]

Output
[1,2,3,4,5,6,7]

Expected
[5,6,7,1,2,3,4]

Despite the fact that nums is the correct order in my final reverse. Where am I going wrong?

Answer

This:

nums = nums[::-1]

assigns nums to a new list. All of the operations you subsequently perform on nums are not on the list you originally pass into the function.

You’re looking for:

nums[:] = nums[::-1]

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Answer