快速排序算法

近来想学习一下python很算法，用python实现了一下快速排序：

#python


def quick_sort(array, length):
    if length < 2 :
        #"array is too short to sort"
        return
    startValue = array[0]
    i = 0
    j = length - 1

    while(i < j):
        while(j > i):
            if array[j]<array[i]:
                array[i] = array[j]
                ++i;
                break;
            j = j - 1;

        while(i < j):
            if array[i]>array[j]:
                array[j] = array[i]
                --j
                break;
            i = i + 1;
    array[i] = startValue
    quick_sort(array,i)
    quick_sort(array[i+1:],length - i -1)


array = [6,2,7,3,8,9]

print("before sort array = %r" % repr(array))
quick_sort(array,len(array))
print("after sort array = %r" % repr(array))