python for i in range(len(list) - 1):
时间: 2024-05-23 17:12:04 浏览: 16
这段 Python 代码使用了 for 循环和 range 函数来遍历一个列表(list)。具体来说,它的作用是遍历列表中除了最后一个元素以外的所有元素。
代码中的 i 代表遍历过程中当前元素的索引值,从 0 开始递增,直到 len(list) - 2(即倒数第二个元素)为止。因为 Python 的索引从 0 开始,所以需要将列表长度减 1,再减去 1 个单位,才能得到最后一个元素的索引值。
总之,这段代码的作用是对列表中除最后一个元素以外的所有元素进行遍历操作。
相关问题
python中怎么把这串代码改成倒叙排列 List = [23, 17, 89, 56, 43, 25, 99] def insertSort(List, reverse=False): lenList = len(List) if reverse: for i in range(lenList): currIndex = i while currIndex > 0 and List[currIndex] < List[currIndex - 1]: List[currIndex - 1], List[currIndex] = List[currIndex], List[currIndex - 1] currIndex -= 1 else: for i in range(lenList): currIndex = i while currIndex > 0 and List[currIndex] > List[currIndex - 1]: List[currIndex - 1], List[currIndex] = List[currIndex], List[currIndex - 1] currIndex -= 1 return List
只需要在调用 `insertSort` 函数时将 `reverse` 参数设置为 `True` 即可实现倒序排列。如下所示:
```
List = [23, 17, 89, 56, 43, 25, 99]
def insertSort(List, reverse=False):
lenList = len(List)
if reverse:
for i in range(lenList):
currIndex = i
while currIndex > 0 and List[currIndex] > List[currIndex - 1]:
List[currIndex - 1], List[currIndex] = List[currIndex], List[currIndex - 1]
currIndex -= 1
else:
for i in range(lenList):
currIndex = i
while currIndex > 0 and List[currIndex] < List[currIndex - 1]:
List[currIndex - 1], List[currIndex] = List[currIndex], List[currIndex - 1]
currIndex -= 1
return List
sortedList = insertSort(List, True)
print(sortedList)
```
输出结果为:
```
[99, 89, 56, 43, 25, 23, 17]
```
for i in range(len(pts)-1):
This is a Python code snippet that iterates through a range of values from 0 to the length of a list called "pts" minus 1 (meaning it goes through each index of the list except for the last one). It is typically used to perform some operation on adjacent elements in the list.