Grasshopper Data Tree to Python

Hello, Can somebody please help me ??

I am wanting to be able to convert a grasshopper data tree into python so that I can access certain pieces of data only.

I am new to python and am not sure exactly how to convert the datatree into python .. I am importing this .shp file https://drive.google.com/file/d/0BySL_YFrwgAuTTAzeVlacFdFXzA/view?u...

and I want to only use the 'RELHMAX' data list

this is what my script looks like so far (see attached)

please please help me - I will be extremely grateful for any advice!