when wanting to make calls for Cocoa on OS X platform
consider the Objective C calls first
make it work with Objective C and Xcode first
once it is working there, it should be easy to wrap those calls with something like PyObjC... but until then, that might just get in the way. Need to define what it is that you want to do first.
This is the main introduction to Cocoa:
It recommends knowing about the Mac OS X Technologies, described in the following document:
In particular, the following section on Graphics and Multimedia Technologies seems relevant:
Talking about Quartz, the 2D rendering engine for window layouts.