Strange behavior

[Pedro Ferreira]

Hello.
I'm sorry if the question is dumb, but... considering the following
segment of code:

from rdflib.Graph import ConjunctiveGraph

g = ConjunctiveGraph()
fd = open('test.rdf','r')

g.parse(fd)
res1 = g.query("SELECT ?x ?y ?z WHERE {?x ?y ?z .}")

res2 = []
t = g.triples((None,None,None))
for r in t :
res2.append(r)

print len(res1), len(res2)


shouldn't the output be N, N , being N the number of triples in the
RDF graph? Strangely, the query is not working for me. Maybe I'm not
using it in the right way?

Thanks in advance,

Pedro

[Sidney]

Try this: print res1

'res1' is a sparql query result, which is different then a set of triples.

Try this instead:

res1 = g.query("CONSTRUCT { ?x ?y ?z } WHERE { ?x ?y ?z }")
triples1 = list(res1.triples((None,None,None)))

res2 = list(g.triples((None,None,None))

print len(triples1), len(res2)

....

They should be the same.

SELECT will return a sparql query result type. See module
rdflib.sparql.QueryResult for available serialization methods.

CONSTRUCT, DESCRIBE will return a graph.

ASK will return a boolean.

Best of luck.

[Pedro Ferreira]

I get this error:

Traceback (most recent call last):
File "testrdflib.py", line 15, in <module>
triples1 = list(res1.triples((None,None,None)))
AttributeError: 'SPARQLQueryResult' object has no attribute 'triples'

Thanks for your help,

Pedro

[Pedro Ferreira]

Hello.
OK, I guess you meant:

res1 = g.query("CONSTRUCT { ?x ?y ?z } WHERE { ?x ?y ?z }")

triples1 = list(list(res1)[0].triples((None,None,None)))

res2 = list(g.triples((None,None,None)))


but the result is the same :(

Cheers,

Pedro

[Pedro Ferreira]

OK, it's solved. I was using the dev branch, whose sparql support was
broken...