"definitive" source on advanced python?

[shalabh.chaturvedi at gmail.com]

You might find http://www.cafepy.com/article/python_types_and_objects/
and http://www.cafepy.com/article/python_attributes_and_methods/
useful. These articles assume you know Python, and describe some of the
mechanisms behind Python new-style objects - including descriptors (but
not decorators).