How to check if an ElementType is placed in revit model?

Question

I have collected element types using following code in Ironpython:

typeelements =  DB.FilteredElementCollector(revit.doc)\
                    .OfClass(DB.ElementType)\
                    .ToElements()

How to know whether an element collected in typeelements is present in Revit model space?

Answer 1

Implement another filtered element collector filtering for all family instances of the given type. More efficiently, just retrieve all family instances in one single go. From that list, you can determine all the types being used in the model.