ghpythonutil is a lightweight utility library for Grasshopper Python scripting.
For those who must work with Data Trees, TreeHandler is a function decorator for handling Data Trees as inputs in user-defined functions. Calls to decorated functions will avoid implicit looping behavior triggered by component inputs with item access or list access. The decorator will handle DataTree input in a fashion identical to any other default grasshopper component.
Download treehandler_library_and_definitions.zip, and place the folder <ghpythonutil> in one of the sys.paths printed from a GhPython module.
Usage: Instructions on Github