Utilisation de contextes dans rdflib

Question

Je n'arrive pas à trouver un exemple clair et raisonnable d'utilisation du contexte avec rdflib. ConjunctiveGraph n'accepte pas les contextes et Graph est obsolète. Comment suis-je supposé créer et opérer sur différents contextes au sein du même ConjunctiveGraph global?

Answer 1

Oui. Voici le code

import rdflib 
from rdflib.Graph import Graph 

conj=rdflib.ConjunctiveGraph() 

NS=rdflib.Namespace("http://example.com/#") 
NS_CTX=rdflib.Namespace("http://example.com/context/#") 

alice=NS.alice 
bob=NS.bob 
charlie=NS.charlie 

pizza=NS.pizza 
meat=NS.meat 
chocolate=NS.chocolate 

loves=NS.loves 
hates=NS.hates 
likes=NS.likes 
dislikes=NS.dislikes 

love_ctx=Graph(conj.store, NS_CTX.love) 
food_ctx=Graph(conj.store, NS_CTX.food) 

love_ctx.add((alice, loves, bob)) 
love_ctx.add((alice, loves, charlie)) 
love_ctx.add((bob, hates, charlie)) 
love_ctx.add((charlie, loves, bob)) 

food_ctx.add((alice, likes, chocolate)) 
food_ctx.add((alice, likes, meat)) 
food_ctx.add((alice, dislikes, pizza)) 

print "Full context" 
for t in conj: 
    print t 

print "" 
print "Contexts" 
for c in conj.contexts(): 
    print c 

print "love context" 
for t in love_ctx: 
    print t 

print "food context" 
for t in food_ctx: 
    print t 

Et ceci est la sortie

Full context 
(rdflib.URIRef('http://example.com/#bob'), rdflib.URIRef('http://example.com/#hates'), rdflib.URIRef('http://example.com/#charlie')) 
(rdflib.URIRef('http://example.com/#alice'), rdflib.URIRef('http://example.com/#likes'), rdflib.URIRef('http://example.com/#chocolate')) 
(rdflib.URIRef('http://example.com/#alice'), rdflib.URIRef('http://example.com/#likes'), rdflib.URIRef('http://example.com/#meat')) 
(rdflib.URIRef('http://example.com/#alice'), rdflib.URIRef('http://example.com/#dislikes'), rdflib.URIRef('http://example.com/#pizza')) 
(rdflib.URIRef('http://example.com/#alice'), rdflib.URIRef('http://example.com/#loves'), rdflib.URIRef('http://example.com/#bob')) 
(rdflib.URIRef('http://example.com/#alice'), rdflib.URIRef('http://example.com/#loves'), rdflib.URIRef('http://example.com/#charlie')) 
(rdflib.URIRef('http://example.com/#charlie'), rdflib.URIRef('http://example.com/#loves'), rdflib.URIRef('http://example.com/#bob')) 

Contexts 
<http://example.com/context/#food> a rdfg:Graph;rdflib:storage [a rdflib:Store;rdfs:label 'IOMemory']. 
<http://example.com/context/#love> a rdfg:Graph;rdflib:storage [a rdflib:Store;rdfs:label 'IOMemory']. 
love context 
(rdflib.URIRef('http://example.com/#bob'), rdflib.URIRef('http://example.com/#hates'), rdflib.URIRef('http://example.com/#charlie')) 
(rdflib.URIRef('http://example.com/#alice'), rdflib.URIRef('http://example.com/#loves'), rdflib.URIRef('http://example.com/#bob')) 
(rdflib.URIRef('http://example.com/#alice'), rdflib.URIRef('http://example.com/#loves'), rdflib.URIRef('http://example.com/#charlie')) 
(rdflib.URIRef('http://example.com/#charlie'), rdflib.URIRef('http://example.com/#loves'), rdflib.URIRef('http://example.com/#bob')) 
food context 
(rdflib.URIRef('http://example.com/#alice'), rdflib.URIRef('http://example.com/#likes'), rdflib.URIRef('http://example.com/#chocolate')) 
(rdflib.URIRef('http://example.com/#alice'), rdflib.URIRef('http://example.com/#likes'), rdflib.URIRef('http://example.com/#meat')) 
(rdflib.URIRef('http://example.com/#alice'), rdflib.URIRef('http://example.com/#dislikes'), rdflib.URIRef('http://example.com/#pizza'))