#!/usr/bin/env python# -*- coding: utf-8 -*-def quick_sort(arr):    l = len(arr)    _quick_sort(arr, 0, l -1)tmp = 0def _quick_sort(arr, start, end):    print  start,end    if start >= end:        return    middle = partition(arr, start, end)    _quick_sort(arr, start, middle - 1)    _quick_sort(arr, middle + 1, end)def partition(arr, start, end):    i = (start+end)/2    while(start < end):        while(start < end and arr[start] <= arr[i]):            start = start + 1        while(start < end and arr[end] >= arr[i]):            end = end - 1        if start < end:            arr[start], arr[end] = arr[end], arr[start]    if start > i and  start - 1 != i :        arr[start -1],arr[i] = arr[i], arr[start - 1]        i = start -1    elif start < i :        arr[start], arr[i] = arr[i], arr[start]        i = start    return iarr = [1,3,9,3,4,8,8,9]quick_sort(arr)