An introduction to PyObjC describes the general method for translating Objective-C calls into Python calls, including the handling of pass-by-reference arguments and buffers.
This document describes where the PyObjC bindings for this framework are different from the general rule, such as mentioning APIs that are not supported or where the interface is different than expected.
The C API for creating plugin bundles is not supported. Use the Objective-C API instead.
ABPickerSetDelegate and ABPickerGetDelegate use an API that isn’t wrapped by PyObjC.
The C API has some problems on Snow Leopard, use the Object-Oriented API instead.