Hi guys. If you want to fiddle with the Rhino document from GHPython, you must explicitly set the script context to target the Rhino document. Here’s one approach:
import Rhino as rc
import scriptcontext as sc
import rhinoscriptsyntax as rs
# Set context to Rhino document and disable redraw
sc.doc = rc.RhinoDoc.ActiveDoc
rs.EnableRedraw(False)
# Fiddle with the Rhino document
# Set context back to Grasshopper
rs.EnableRedraw(True)
sc.doc = ghdoc