skolemize.py

"""Untill https://github.com/RDFLib/rdflib/pull/807 is merged and released."""
from rdflib import Graph, BNode, URIRef
from six.moves.urllib.parse import urljoin

"""requirements.txt:

rdflib>=4.2.2
"""

def bNodeSkolemize(self, authority=None, basepath=None):
    """ Create a URIRef "skolem" representation of the BNode, in accordance
    with http://www.w3.org/TR/rdf11-concepts/#section-skolemization

    .. versionadded:: 4.0
    """
    rdflib_skolem_genid = "/.well-known/genid/rdflib/"
    if authority is None:
        authority = "http://rdlib.net/"
    if basepath is None:
        basepath = rdflib_skolem_genid
    skolem = "%s%s" % (basepath, str(self))
    return URIRef(urljoin(authority, skolem))


def skolemize(self, new_graph=None, bnode=None, authority=None, basepath=None):
    def do_skolemize(bnode, t):
        (s, p, o) = t
        if s == bnode:
            s = bNodeSkolemize(s, authority=authority, basepath=basepath)
        if o == bnode:
            o = bNodeSkolemize(o, authority=authority, basepath=basepath)
        return (s, p, o)

    def do_skolemize2(t):
        (s, p, o) = t
        if isinstance(s, BNode):
            s = bNodeSkolemize(s, authority=authority, basepath=basepath)
        if isinstance(o, BNode):
            o = bNodeSkolemize(o, authority=authority, basepath=basepath)
        return (s, p, o)

    retval = Graph() if new_graph is None else new_graph

    if bnode is None:
        self._process_skolem_tuples(retval, do_skolemize2)
    elif isinstance(bnode, BNode):
        self._process_skolem_tuples(
            retval, lambda t: do_skolemize(bnode, t))

    return retval


inputUri = "file.ttl"
graph = Graph()
graph.parse(inputUri, format="ttl")
skolemGraph = skolemize(graph, authority="http://ub.uni-leipzig.de", basepath="mobigames/")
skolemGraph.serialize(destination="skolemized.ttl", format='ttl')