英文:
removing a duplicated item from a python list
问题
I'm tring to remove the maximum value from a list that has a repeated maximum value for example: [1,3,6,6,5] the code i use only removes one of the values wihtout removing the other. any ideas why is that happening? the code i use is:
我正在尝试从一个具有重复的最大值的列表中删除最大值，例如：[1,3,6,6,5] 我使用的代码只删除一个值，而没有删除另一个。有什么想法为什么会发生这种情况？我使用的代码是：
n = int(input())
arr = map(int, input().split())
lst = list(arr)
for i in lst:
if i == max(lst):
del(lst[lst.index(i)])
print(max(lst))
英文:
I'm tring to remove the maximum value from a list that has a repeated maximum value for example: [1,3,6,6,5]
the code i use only removes one of the values wihtout removing the other. any ideas why is that happening? the code i use is:
n = int(input())
arr = map(int, input().split())
lst = list (arr)
for i in lst:
if i == max(lst):
del(lst[lst.index(i)])
print (max(lst))
答案1
得分: 1
以下是翻译好的部分：
这段代码存在问题：
for i in lst:
if i == max(lst):
del(lst[lst.index(i)])
正如@AllanWind所评论的，当您调用del来从列表中删除项目时，这会改变列表的大小，导致外部的for i in lst循环与实际的列表内容不同步。
在迭代列表时不要添加/删除项目。
对于这种特定用例，下面的代码会更好：
m = max(lst)
while m in lst:
lst.remove(m)
英文:
This code is the problem:
for i in lst:
if i == max(lst):
del(lst[lst.index(i)])
As @AllanWind commented, when you call del to remove the item from the list, this changes the size of the list, which causes the outer for i in lst loop to get out of sync with the actual list contents.
Don't add/remove items to a list as you're iterating over it.
For this specific use case, this code would be a lot better:
m = max(lst)
while m in lst:
lst.remove(m)
答案2
得分: 0
你可以使用一个筛选器（如果你希望将结果分配给相同的 lst）：
lst = [1, 3, 6, 6, 5]
lst2 = list(filter(lambda f: f != max(lst), lst))
英文:
You could use a filter (and if you wish assign the result to the same lst):
lst = [1, 3, 6, 6, 5]
lst2 = list(filter(lambda f: f != max(lst), lst))
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