---

def quick_sort(arr):
    if len(arr) <= 1:
        return arr
    pivot = arr[len(arr) // 2]  # опорный элемент
    left = [x for x in arr if x < pivot]
    mid = [x for x in arr if x == pivot]
    right = [x for x in arr if x > pivot]
    return quick_sort(left) + mid + quick_sort(right)

print(quick_sort([3, 6, 1, 8, 2, 9]))  # [1, 2, 3, 6, 8, 9]