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[英]Slice indices must be integers or None or have an __index__ method error?
[英]TypeError: slice indices must be integers or None or have an __index__ method
在 IDLE 中运行代码时会出现以下错误:
Traceback (most recent call last): File "C:/Python34/inversion3.py",
line 44, in <module>
nInversions.inversionMergeSort(m) File "C:/Python34/inversion3.py", line 16, in inversionMergeSort
left = m[0:half] TypeError: slice indices must be integers or None or have an __index__ method
代码:-
from collections import deque
m = []
f = open("IntegerArray.txt")
for line in f:
m.append(int(line))
class InversionCount:
def __init__(self, n):
self.n = n
def inversionMergeSort(self, m):
if len(m) <= 1:
return m
half = len(m)/2
left = m[0:half]
right = m[half:]
left = self.inversionMergeSort(left)
right = self.inversionMergeSort(right)
return self.inversionSort(left, right)
def inversionSort(self, left, right):
leftQueue = deque(i for i in left)
rightQueue = deque(j for j in right)
orderedList = []
while len(leftQueue) > 0 or len(rightQueue) > 0:
if len(leftQueue) > 0 and len(rightQueue) > 0:
if leftQueue[0] <= rightQueue[0]:
orderedList.append(leftQueue[0])
leftQueue.popleft()
else:
orderedList.append(rightQueue[0])
self.n += len(leftQueue)
rightQueue.popleft()
elif len(leftQueue) > 0:
orderedList.append(leftQueue[0])
leftQueue.popleft()
elif len(rightQueue) > 0:
orderedList.append(rightQueue[0])
rightQueue.popleft()
return orderedList
nInversions = InversionCount(0)
nInversions.inversionMergeSort(m)
print (nInversions.n)
在3.x中,int / int给出一个浮点数。 这不是一个int。
>>> 3/2
1.5
所以你的第15行
half = len(m)/2
让一半浮动。 你需要的是双斜线
half = len(m)//2
根据需要在第16行的切片中使用半个int。
在你的情况下, len(m)/2
返回一个float
,第16行期望一个int
。
您应该将cast half键入int
,如下所示:
left = m[0:int(half)]
仅使用 / 这会给您带来浮点数,您需要使用 // 才能将结果提供给 integer。
这将解决错误。 它对我有用
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