code: def _namespace_from_uri(self, uri):
          
          # TODO - this could be helped a bunch with proper use of the graph API
          # it seems a bit fragile to treat these as simple string-splits
          uri = str(uri)
          parts = uri.split('#')
          if len(parts) == 1:
              return "%s/" % '/'.join(uri.split('/')[:-1])
          return "%s#" % '#'.join(parts[:-1])
docs: returns the expanded namespace prefix of a uri