快速排序-python

def qsort(a, si, ei):
if si >= ei:
return
key = a[si]
i = si
j = ei
while i != j:
while i < j and key <= a[j]:
j = j - 1
a[i], a[j] = a[j], a[i]
while i < j and a[i] <= key:
i = i + 1
a[i], a[j] = a[j], a[i]
qsort(a, si, i-1)
qsort(a, i+1, ei)

if __name__ == '__main__':
testArr   = [4, 7, 2, 90, 44]
resultArr = [2, 4, 7, 44, 90]
qsort(testArr, 0, len(testArr) - 1)
print(testArr)
print(resultArr == testArr)