Filter with boolean mark


I am working on a small Dynamo project where I have a list from excel and a list with information (Code) from Revit.
I like to update the Revit elements with information from the Excel list based on the rows in the Excel file that have te same code.
But how do I filter out the rows from the Excel list that have the same code from the Revit list.

Here is my Example:
I am trying to figure out how to create a boolean mark list from two lists.
I have a list (1) and like create a new list (3) with only the elements from list (1) that are te same in list (2).
This example gives me only one True value.
What am I doing wrong here?

filter by boolian mark example.dyn (5.0 KB)

Hello Robert,
I would suggest a different workflow for comparing values from excel to values from Revit. Have look at this post:

1 Like


This helped a lot.