Datatree [gh] to loop [python]...

So i have a script that i have been working on in python for a hexagonal pattern based off of a UV coordinate system. [http://jluebker.wordpress.com/2013/04/10/hexagonal-grid-on-surface-...]. I am trying to get this to work in grasshopper to begin to add some additional funcationality to the varied UV system. But first i need to figure out how to translate between the datatree branches and the loop in python. I am currently using a dictionary with the following logic: PtMtx[(i,j)].

Does anyone know of a way to translate a data tree in to a python dictionary?