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 FSEvents package contains wrappers for the FSEvents API’s, which are part of Carbon and not a standalone framework.
The FSEventsRef type is an opaque pointer, unlike what the name suggests this is not a CoreFounation based types. As a side-effect of that the programmer is responsibly for managing the retain-count of objects of this type.
This means you have to call FSEventStreamRelease when you’re done with a stream. You must not use the stream after that, it will then refer to an invalid stream.