Importing py files in a specific folder

import sys;
sys.path.insert(0, folderfullpath);

#--------------------------------------------------
# i3d.pyc file is stored in user/maya/scripts/
# All other i3d pyc files are stored in user/maya/scripts/i3d/
import sys, i3d as i3d;
sys.path.insert(0, i3d.geti3dfolder());