To use the PDBpy class, you will also need the FileBasics.py and Geo3DUtils.py.
If you have a copy of the PDB somewhere on your workstation, you may edit
the PDBPATH variable at the top of PDBpy.py file to setup its proper path.
Doing so, PDB files will be automatically loaded by simply invoking:
x= PDB("1tim") for example. (This will look for the PDBPATH/all/pdb/pdb1tim.ent.gz file.)
The use is then quite straightforward.