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 entire CoreLocation framework is supported
kCLErrorGeocodeFoundNoResult, kCLErrorGeocodeCanceled
These contants have different values in the OSX 10.7 and 10.8 SDKs. With PyObjC you get the value corresponding to the OSX release you are running on.