lightrdf.Error: error while parsing IRI '': No scheme found in an absolute IRI about lightrdf HOT 2 OPEN

I'm sorry for the late reply. Thank you for the very clear report!

A quick solution is to specify base_iri of parse() to some absolute URI (like https://ftp.uniprot.org/pub/databases/uniprot/current_release/rdf/pathways.rdf.xz):

import lightrdf
import sys

parser = lightrdf.Parser()

cnt = 0

for triple in parser.parse(sys.argv[1], base_iri="https://ftp.uniprot.org/pub/databases/uniprot/current_release/rdf/pathways.rdf.xz"):
    cnt += 1

print(cnt)

More specifically, the problem is <owl:Ontology rdf:about=""> in pathways.rdf, for rdf:about="" means "the URI of the document containing the ontology" (as stated in OWL1/2 specs and in general), but there is no definitive URI/IRI for downloaded local files.

RDFLib avoids this problem by using the local IRI of the file (file:///.../pathways.rdf) for base IRI by default.
We may make lightrdf do the same thing, but before that I'd like to investigate if it is reasonable.

from lightrdf.

Thanks for your reply @ozekik!

I think the best solution would be to put your example in the README, as the base IRI default setting might be more confusing in other situations.

from lightrdf.