If you find Gtk.Treeview and Gtk.Treemodel hard to use, then liblarch is probably for you.
Liblarch is a python library built to easily handle data structure such are lists, trees and acyclic graphs (tree where nodes can have multiple parents). There's also a liblarch-gtk binding that will allow you to use your data structure into a Gtk.Treeview.
Liblarch support multiple views of one data structure and complex filtering. That way, you have a clear separation between your data themselves (Model) and how they are displayed (View).
Liblarch is published under the LGPLv3 license.