快速排序

a_list = [12,13,4,5,1,10,7]
a_low = 0
a_high = 6
def quick_sort(l,low,high):
    pivotkey = l[low]
    while (low<high):
        while (low<high and l[high]>=pivotkey):
            high-=1
        l[low],l[high] = l[high],l[low]
        while (low<high and l[low]<=pivotkey):
            low+=1
        l[low],l[high] = l[high],l[low]
    print low
    print l
    return low

def q_sort(l,low,high):
    if low<high:
        pivotloc = quick_sort(l,low,high)
        q_sort(l,low,pivotloc-1)
        q_sort(l,pivotloc+1,high)
q_sort(a_list,a_low,a_high)
print a_list