At present, the urdf_parser_py page on ROS.org seems a bit mixed up:
http://wiki.ros.org/urdf_parser_py
It refers to the old robot_model_py package, and indicates that it's only supported for EOL packages; it then mentions that its been renamed to urdfdom_py; if you click on that link, it takes you to that page which actually refers to the urdf_parser_py page?
http://wiki.ros.org/urdfdom_py
It does seem that robot_model_py does still have its old page:
http://wiki.ros.org/robot_model_py
A wee bit confusing...