def partition(array, low, high):

  pivot = array[high]

  i = low - 1

​

  for j in range(low, high):

     if array[j] <= pivot:

       i += 1

       array[i], array[j] = array[j], array[i]

​

  array[i+1], array[high] = array[high], array[i+1]

  return i+1

​

def quicksort(array, low=0, high=None):

  if high is None:

    high = len(array) - 1

​

  if low < high:

    pivot_index = partition(array, low, high)

    quicksort(array, low, pivot_index-1)

    quicksort(array, pivot_index+1, high)

​

mylist = [64, 34, 25, 5, 22, 11, 90, 12]

quicksort(mylist)

print(mylist)

​