Hello,
I would like to know if it’s possible to take the ID of the elements from a list (the list is shown in the image below). Is it also possible to take only the ID of the elements counted as “false”?
Hi 
Try the Element.Id node.
Try playing with List.FilterByBoolMask to filter those element first, then query their IDs with Element.Id
Thanks for your reply. I’ve probably solved with this but I got an error message (Waring: Asked to convert non-convertible types). Do you know why?
You’re passing a parameter value to Element.Name, not a an element.
I was doing the same also before and it was working properly. If i pass from Element.GetParameterValueByName directly to the input of == function, the script gives me wrong results (everything is correct).
Really hard to tell without all the previews of the nodes activated…
We could be speaking about bananas or strawberries, I’ll have no clue of it.
2 Likes
You are right.
Here the two different scenarios.
In the first case I’m using Element.name between the Element.GetParameterValueByName and the == function: the results I got are reliable. In the second case I’m not using Element.name between the Element.GetParameterValueByName and the == function, but I’ve linked them together directly: the results I got are not reliable.
I know for sure that my result should be 12 correct and 1 wrong.
Any suggestion?
I think you did not get my previous message 
Otherwise, we cannot know where the error may be.
Use a “Phases” node in lieu of the code block before the “=” node. This will compare the Phase element not the Name/String of the phase.
The problem is cercled in red. One of the parameters of your walls is not correctly informed : it should be a Phase but it is a string. If you want to delete the error, you should correct this directly in the model.
You could also filter those elements using the Object.Type node, but i’d recommend correcting the model.
It makes sense but it doesn’t work as shown in the figure below. I know that I have 12 elements on the phase “stato di fatto” and 1 on the phase “stato di progetto”.
Try using the Object A = Object B node in lieu of == since you are comparing elements. But that still doesn’t resolve why there is an element not on a proper phase per the response from @mellouze.
I can see that it seems like if Dynamo doesn’t recognize the phase “Stato di Progetto”, but as you can see from the pictures below, I think that the model is correct.
Thanks for helping me. Where can I find this Object A = Object B node? Anyway, as you can see from the picture I’ve uploaded under the Mellouze’s reply, I cannot understand if there is an error in the model… in my opinion the model is correct
See my image above. This is a built-in node actually called “Equals”.
Have you tried to adjust the lacing? You may want to try “longest” to see if that give you the results you need.
May I ask what Dynamo version and Revit version you are using?
Now it works! Thanks a lot Sean. Even if this problem is solved, I cannot solved the problem with the phase “Stato di Progetto”. Dynamo doesn’t recognize it as a phase, but I really don’t understand why.
Anyway, thanks again for helping me