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lawlesst/rdflib_stardog.py

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  1. lawlesst revised this gist Sep 3, 2015. 1 changed file with 2 additions and 0 deletions.
    2 changes: 2 additions & 0 deletions rdflib_stardog.py
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    Example code for connecting to Stardog (http://stardog.com/) with
    Python's RDFLib (http://github.com/rdflib).
    See longer description: http://lawlesst.github.io/notebook/rdflib-stardog.html
    """


  2. lawlesst created this gist Nov 3, 2014.
    69 changes: 69 additions & 0 deletions rdflib_stardog.py
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    """
    Example code for connecting to Stardog (http://stardog.com/) with
    Python's RDFLib (http://github.com/rdflib).
    """


    from rdflib import Graph, Literal, URIRef
    from rdflib.namespace import RDF, SKOS
    from rdflib.plugins.stores import sparqlstore

    #Define the Stardog store
    endpoint = 'http://localhost:5820/demo/query'
    store = sparqlstore.SPARQLUpdateStore()
    store.open((endpoint, endpoint))

    #Identify a named graph where we will be adding our instances.
    default_graph = URIRef('http://example.org/default-graph')
    ng = Graph(store, identifier=default_graph)

    #Load our SKOS data from a file into an in-memory graph.
    g = Graph()
    g.parse('./sample-concepts.ttl', format='turtle')

    #Serialize our named graph to make sure we got what we expect.
    print g.serialize(format='turtle')


    #Issue a SPARQL INSERT update query to add the assertions
    #to Stardog.
    ng.update(
    u'INSERT DATA { %s }' % g.serialize(format='nt')
    )

    #Query the data using the RDFLib API.

    #All concepts in the Stardog named graph.
    for subj in ng.subjects(predicate=RDF.type, object=SKOS.Concept):
    print 'Concept: ', subj

    #Find concepts that are broader than others
    for ob in ng.objects(predicate=SKOS.broader):
    print 'Broader: ', ob

    #Use RDFLib to issue SPARQL read queries.

    #Bind a prefixe for SKOS so we can use it in our SPARQL queries
    store.bind('skos', SKOS)

    rq = """
    SELECT ?s ?label
    WHERE {
    ?s a skos:Concept ;
    skos:preferredLabel ?label .
    }
    """
    for s, l in ng.query(rq):
    print s.n3(), l.n3()


    #Add a new assertion using the RDFLib API
    soccer = URIRef('http://example.org/n1000')
    ng.add((soccer, SKOS.altLabel, Literal('Football')))


    #Read statements about soccer
    for s, p, o in ng.triples((soccer, None, None)):
    print s.n3(), p.n3(), o.n3()
    15 changes: 15 additions & 0 deletions sample-concepts.ttl
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    @prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
    @prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
    @prefix skos: <http://www.w3.org/2004/02/skos/core#> .
    @prefix xml: <http://www.w3.org/XML/1998/namespace> .
    @prefix xsd: <http://www.w3.org/2001/XMLSchema#> .

    <http://example.org/n1234> a skos:Concept ;
    skos:broader <http://example.org/n5678> ;
    skos:preferredLabel "Baseball" .

    <http://example.org/n5678> a skos:Concept ;
    skos:preferredLabel "Sports" .

    <http://example.org/n1000> a skos:Concept ;
    skos:preferredLabel "Soccer" .