Use Civil3DToolkit nodes in python

Civil3D
2 
clr.AddReference('AutoCADNodes')
clr.AddReference('Civil3DNodes')   
clr.AddReference('Autodesk.Civil3DToolkit')  // import the assembly
import Autodesk.AutoCAD.DynamoNodes as DA  // assign alias for AutoCAD nodes
import Autodesk.Civil.DynamoNodes as DC  // assign alias for Civil 3D nodes