Hi,
that page was written for the 4.20 release, because we made a lot of improvements and made the process more consistent. There are also improvements to the Python scripting plugin in 4.20, and the EditorScriptingUtilities plugin. I’d definitely suggest updating to 4.20 if that’s at all possible for you.
That said, I just looked at my 4.19.2 install, and if you’re importing a .udatasmith file the Python and Blueprint APIs look the same as what’s described on that doc page for 4.20.
Also, if you use the DatasmithCADScene to convert a native CAD file instead of a .udatasmith file, you’ll have to call its process_scene() method after you call construct_datasmith_scene_from_file(), but before import_scene().
That method is no longer required in 4.20.