Hãy thực thi thuật toán sắp xếp sáp nhập (merge sort) bằng Python?

def mergeSort(myList):
    if len(myList) > 1:
        mid = len(myList) // 2
        left = myList[:mid]
        right = myList[mid:]
        # Recursive call on each half
        mergeSort(left)
        mergeSort(right)
        # Two iterators for traversing the two halves
        i = 0
        j = 0
        # Iterator for the main list
        k = 0
        while i < len(left) and j < len(right):
            if left[i] < right[j]:
              # The value from the left half has been used
              myList[k] = left[i]
              # Move the iterator forward
              i += 1
            else:
                myList[k] = right[j]
                j += 1
            # Move to the next slot
            k += 1
        # For all the remaining values
        while i < len(left):
            myList[k] = left[i]
            i += 1
            k += 1
        while j < len(right):
            myList[k]=right[j]
            j += 1
            k += 1
myList = [54,26,93,17,77,31,44,55,20]
mergeSort(myList)
print(myList)