Why am I getting this error? (File attached)

Im creating a wireframe van using python code but it only loads vertexes and not edges.python generates an error. try it for yourself.

File is here: http://www.pasteall.org/blend/37479

Python code is attached (jbeam input script.blend) open in notepad or notpad++ copy and paste the text into Blender Python window to duplicate error.

Attachments

jbeam import script.blend (27.1 KB)