Mod_python error: "PythonHandler mod_python.publisher"

Traceback (most recent call last):

  File "/usr/lib/python2.4/site-packages/mod_python/apache.py", line 193, in Dispatch
    result = object(req)

  File "/usr/lib/python2.4/site-packages/mod_python/publisher.py", line 135, in handler
    module = apache.import_module(module_name, _req, [path])

  File "/usr/lib/python2.4/site-packages/mod_python/apache.py", line 335, in import_module
    module = imp.load_module(mname, f, p, d)

  File "/home/pipian/public_html/pipian/rdf/places/index.py", line 8, in ?
    import RDF

ImportError: No module named RDF