[英]Remove nested lists from a list if nested list contains a certain value
I have a nested list and I would like to remove the empty list []
and any nested list that has a value of -1
in it.我有一个嵌套列表,我想删除空列表[]
以及其中值为-1
的任何嵌套列表。 Here is what I have so far, it was working earlier but I think jupyter was being buggy.这是我到目前为止所拥有的,它工作得更早,但我认为 jupyter 有问题。
regions = [[], [2, -1, 1], [4, -1, 1, 3], [5, 0, -1, 4], [9, 10, 7, 8],
[7, 6, 10], [8, 0, 5, 6, 7], [9, 2, 1, 3, 10],
[9, 2, -1, 0, 8], [10, 3, 4, 5, 6]]
counter = range(len(regions))
for region in counter:
print(region)
for i in range(len(regions[region])): # IndexError: list index out of range
#print(regions[region])
if regions[region][i] == -1:
regions.remove(regions[region])
break
print(regions)
I think the issue is when I am removing a region from the regions list, the counter for the regions nested list is modified and that makes me run out of index values before I finish iterating through each nested list.我认为问题是当我从区域列表中删除一个区域时,区域嵌套列表的计数器被修改,这使我在完成遍历每个嵌套列表之前用完了索引值。
Also does my approach even make sense or is there a more native solution that I am overlooking (such as some sort of list comprehension, lambda, filter, etc)?我的方法是否也有意义,或者是否有我忽略的更原生的解决方案(例如某种列表理解、lambda、过滤器等)?
You can simply use this list comprehension:您可以简单地使用此列表推导:
regions = [i for i in regions if i and (-1 not in i)]
Output: Output:
[[9, 10, 7, 8], [7, 6, 10], [8, 0, 5, 6, 7], [9, 2, 1, 3, 10], [10, 3, 4, 5, 6]]
you can also use:您还可以使用:
regions = list(filter(lambda r: r and (r.count(-1)==0),regions))
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