Need some help with strange situation

[nilamo]

        while parts_list:
            for p in parts_list:
                # processing
                return

Why loop over the parts_list at all, if you're just going to process the first thing in it?

This seems like a good opportunity for you to try mocking the server's response, so you can test it without needing to log into the server every time. Besides making testing easier, that also means it's easier for us to help, since we don't have to guess what your input is.