Get index of "Empty List"

Revit
1

Hi folks,
I’m struggling with the list now. I’m wondering if I can get the index of Empty List from a list.
Kindly take a look at the picture
Anyone has solutions ? thanks

ASK
ASK.PNG1148×799 153 KB

1 Like
2

Use List.IsEmpty with Longest lacing or list levels.

2 Likes
3

thank you Nick for swift response,
now I’ve got there, what to do next ?

ASK
ASK.PNG816×736 33.9 KB

1 Like
4

You can make a python script,

b=IN[0]
L=[]
for i in b:
if b[i]==True:
L=L+[i]
OUT = L

I don’t know how to implement on this site sorry
In true python it will work… With dynamo I don’t know…

5

You could also use List.FilterByBoolMask, using List.isEmpty as Mask

1 Like
6

@truongbaolam0209 attach a List.AllIndicesOf node to List.IsEmpty with the boolean true as the item input

4 Likes
7

it is not working, could you pls elaborate more ? thanks

8

@awilliams
i can’t get it, could you pls elaborate more ? thanks

10

Assuming you want the indices so that you can then get elements at those same indices, you can just use FilterByBoolMask to filter your elements based on the true/false values you get.

image
image.png1269×691 48.9 KB

11 Likes
11

@awilliams
i’ve got it, many thanks

12

@Nick_Boyts
i’ve got it, you are the man, many thanks

13

hi @Nick_Boyts
last silly question is how to close the topic
thanks

14

Mark the reply that helped you solve the issue as the Solution.
image

1 Like
15

You could just use OOTB List.Clean. it takes care of any list structure

image

image

2 Likes
16

@salvatoredragotta
i’vs got it.thanks

17

@Nick_Boyts
silly me again, i can’t find the Mark Solution

18

image

Go to the post with the answer of your topic and you will find this element

1 Like
19

Make sure you mark the solution for the question you posted about, not any subsequent questions. The whole point of marking a solution is so that other people with the same question can quickly find an answer in your post.

2 Likes