#!/usr/bin/python

## modifying an rdf data store

from rdflib.URIRef import URIRef
from rdflib.Literal import Literal
from rdflib.BNode import BNode
from rdflib.Namespace import Namespace
from rdflib.constants import TYPE

# Import RDFLib's default TripleStore implementation.
from rdflib.TripleStore import TripleStore

## create a namespace object for FOAF
FOAFNS = Namespace("http://xmlns.com/foaf/0.1/")

store = TripleStore('foaf.rdf')

for item in store.subjects() :
    for names in store.objects(item, FOAFNS["name"]) :
        if names == 'Chris Brooks' :
            brooksNode = item


### Now, let's create a new node that'll indicate that I know Prof. Benson.
benson = BNode()
store.add((benson, FOAFNS["name"], Literal("Greg Benson")))
store.add((benson, FOAFNS["name"], Literal("Greg Benson")))
store.add((benson, FOAFNS["title"], Literal("Dr")))
store.add((benson, FOAFNS["homepage"], URIRef("http://www.cs.usfca.edu/~benson")))
store.add((brooksNode, FOAFNS["knows"], URIRef(benson)))

## save to a file as XML/RDF
store.save('foaf3.rdf')