Create array of materials from imported usdz

I’m trying to create a python script that creates an array of all the materials that are in an imported USDZ file. I’ve looked over the Pixar and Nvidia documentation for anything on this and haven’t seen anything.

The ultimate goal is to re-assign materials from our pre-existing mat library using a look-up table, if anyone knows an easier way to accomplish this task.
Cheers for the help!