You create PythonPart and want to set attributes for all sub elements of PythonPart? For instance you have wall and some steel connecting elements in the wall. How to set attributes for these steel elements which are located in the wall?
If wall and elements would be created as separate individual elements you would create attributes for each particular object which would be independent.
So real problem is when you want to use parametric modeling, where you describe with few parameters wall and all connecting elements in the wall for instance. It is very advanced approach, but how you solve defining BIM parameters for each element in the wall, which cannot be selected separately??
Thanks for any suggestion on this topic.