CODEWITHSUNDEEP
pythonrdfrdflib
Betafish
Betafish

Reputation: 1262

Adding triples from a list to graph using python's rdflib framework

I am trying to add triples to a Graph using python's rdflib package. The relations are provided as a list (a particular column in a dataframe)

sampleRelations = ['similarTo', 'brotherOf', 'capitalOf']
g = Graph()

# general relations
gen = Namespace('http://abcd.com/general#')
g.bind('gen',gen)

# Adding predefined relationships
g.add( (gen.relatedTo, RDFS.subClassOf, OWL.ObjectProperty) )

This works as usual. But, when iterating through a list:

for rel in sampleRelations:
    g.add( ('gen.'+rel, RDFS.subClassOf, OWL.ObjectProperty) )

It throws an error : "Subject %s must be an rdflib term" % (s,). 

relWithNamespace = gen+rel
print(relWithNamespace)
g.add( (relWithNamespace, RDFS.subClassOf, OWL.ObjectProperty) )

Error

AssertionError: Subject http://abcd.com/general#similarTo must be an rdflib term

I understand the problem. I'm looking for pointers which can circumvent this.

Upvotes: 0

Views: 3714

Answers (1)

Betafish
Betafish

Reputation: 1262

RDF terms can be of BNode, URI Reference or a Literal 

    sampleRelations = ['similarTo', 'brotherOf', 'capitalOf'`]
    g = Graph()

    # general relations
    gen = Namespace('http://abcd.com/general#')
    g.bind('gen',gen)

    # Adding predefined relationships
    g.add( (gen.relatedTo, RDFS.subClassOf, OWL.ObjectProperty) )
    for rel in sampleRelations :
        rel = URIRef('http://abcd.com/general#' + rel)        
        g.add((rel, RDFS.subClassOf, OWL.ObjectProperty))

URI Reference can be also done using: 

for rel in sampleRelations :                
      g.add((gen.term(rel), RDFS.subClassOf, OWL.ObjectProperty))

or 

for rel in sampleRelations :                
          g.add((gen[rel], RDFS.subClassOf, OWL.ObjectProperty))

Upvotes: 2

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