create a merge sort algorithm in python

main.py
def merge_sort(arr):
    if len(arr) > 1:
        mid = len(arr) // 2
        left_half = arr[:mid]
        right_half = arr[mid:]

        # Recursively sort both halves
        merge_sort(left_half)
        merge_sort(right_half)

        # Merge the sorted halves into a sorted whole
        left_idx = right_idx = sorted_idx = 0
        while left_idx < len(left_half) and right_idx < len(right_half):
            if left_half[left_idx] <= right_half[right_idx]:
                arr[sorted_idx] = left_half[left_idx]
                left_idx += 1
            else:
                arr[sorted_idx] = right_half[right_idx]
                right_idx += 1
            sorted_idx += 1

        # Copy remaining elements to array
        while left_idx < len(left_half):
            arr[sorted_idx] = left_half[left_idx]
            left_idx += 1
            sorted_idx += 1

        while right_idx < len(right_half):
            arr[sorted_idx] = right_half[right_idx]
            right_idx += 1
            sorted_idx += 1

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