"""
SPARQL Queries be prepared (i.e parsed and translated to SPARQL algebra)
by the :meth:`rdflib.plugins.sparql.prepareQuery` method.

When executing, variables can be bound with the
``initBindings`` keyword parameter
"""

import rdflib
from rdflib.plugins.sparql import prepareQuery
from rdflib.namespace import FOAF

if __name__ == "__main__":

    q = prepareQuery(
        "SELECT ?s WHERE { ?person foaf:knows ?s .}", initNs={"foaf": FOAF}
    )

    g = rdflib.Graph()
    g.load("foaf.n3", format="n3")

    tim = rdflib.URIRef("http://www.w3.org/People/Berners-Lee/card#i")

    for row in g.query(q, initBindings={"person": tim}):
        print(row)