how do you get a Mac OS X GUI around this if it is written in python? Can you do the same with perl, php, and other languages? Interface Builder has always been a stumbling block for me to even begin to learn Obj-C or Swift.
It says in the readme he uses wxPython (wxWidgets). You could also use Qt as I believe both use native Cocoa underneath. You can't do everything that is possible if you were coding on Obj-C or Swift, but the stuff you can do looks native. Both have bindings in many languages.
We used wxpython, which uses native GUI elements based on the OS. There are bindings for other a bunch of other languages too: https://www.wxwidgets.org/