Simple examples showing how to use the SPARQLStore
Attributes:
-
HOST– -
count– -
dbo– -
dbr– -
graph– -
pop– -
sparql_store– -
st– -
update_store–
module-attribute
sparql_store = SPARQLStore(query_endpoint='http://fake-sparql-endpoint.com/repository/x', auth=('my_username', 'my_password'))
module-attribute
update_store = SPARQLUpdateStore(query_endpoint='http://localhost:3030/db/sparql', update_endpoint='http://localhost:3030/db/update')
false show_docstring_attributes: false show_docstring_functions: false show_docstring_modules: false show_docstring_classes: false show_signature: false show_signature_annotations: false show_signature_type_parameters: false show_docstring_other_parameters: false show_docstring_parameters: false show_docstring_raises: false show_docstring_receives: false show_docstring_returns: false summary: false show_if_no_docstring: false
import sys
from urllib.request import urlopen
from rdflib import Graph, Namespace, URIRef
from rdflib.namespace import RDF, SKOS
from rdflib.plugins.stores.sparqlstore import SPARQLStore, SPARQLUpdateStore
from rdflib.term import Identifier, Literal
# Shows examples of the useage of SPARQLStore and SPARQLUpdateStore against local SPARQL1.1 endpoint if
# available. This assumes SPARQL1.1 query/update endpoints running locally at
# http://localhost:3030/db/
#
# It uses the same endpoint as the test_dataset.py!
#
# For the tests here to run, you can for example start fuseki with:
# ./fuseki-server --mem --update /db
# THIS WILL ADD DATA TO THE /db dataset
HOST = "http://localhost:3030"
if __name__ == "__main__":
try:
assert len(urlopen(HOST).read()) > 0
except Exception:
print(f"{HOST} is unavailable.")
sys.exit(126)
dbo = Namespace("http://dbpedia.org/ontology/")
dbr = Namespace("http://dbpedia.org/resource/")
# EXAMPLE Update Store:
update_store = SPARQLUpdateStore(
query_endpoint="http://localhost:3030/db/sparql",
update_endpoint="http://localhost:3030/db/update",
)
graph = Graph(store=update_store, identifier="http://dbpedia.org")
graph.add((dbr.Berlin, dbo.populationTotal, Literal(3)))
graph.add((dbr.Brisbane, dbo.populationTotal, Literal(2)))
graph.add((dbr["Category:Capitals_in_Europe"], RDF.type, SKOS.Concept))
graph.add((dbr["Category:Holy_Grail"], RDF.type, SKOS.Concept))
graph.add((dbr["Category:Hospital_ships_of_Japan"], RDF.type, SKOS.Concept))
# EXAMPLE Store 1: using a Graph with the Store type string set to "SPARQLStore"
graph = Graph("SPARQLStore", identifier="http://dbpedia.org")
graph.open("http://localhost:3030/db/sparql")
pop = graph.value(URIRef("http://dbpedia.org/resource/Berlin"), dbo.populationTotal)
assert isinstance(pop, Identifier)
print(
"According to DBPedia, Berlin has a population of {0:,}".format(
int(pop)
).replace(",", ".")
)
print()
# EXAMPLE Query 2: using a SPARQLStore object directly
st = SPARQLStore(query_endpoint="http://localhost:3030/db/sparql")
for p in st.objects(
URIRef("http://dbpedia.org/resource/Brisbane"), dbo.populationTotal
):
assert isinstance(p, Identifier)
print("According to DBPedia, Brisbane has a population of {0}".format(int(p)))
print()
# EXAMPLE Query 3: doing RDFlib triple navigation using SPARQLStore as a Graph()
print("Triple navigation using SPARQLStore as a Graph():")
graph = Graph("SPARQLStore", identifier="http://dbpedia.org")
graph.open("http://localhost:3030/db/sparql")
# we are asking DBPedia for 3 skos:Concept instances
count = 0
for s in graph.subjects(predicate=RDF.type, object=SKOS.Concept):
count += 1
print(f"\t- {s}")
if count >= 3:
break
# EXAMPLE Query 4: doing RDFlib triple navigation using a Graph() with a SPARQLStore backend
print("Triple navigation using a Graph() with a SPARQLStore backend:")
st = SPARQLStore(query_endpoint="http://localhost:3030/db/sparql")
graph = Graph(store=st)
# we are asking DBPedia for 3 skos:Concept instances
count = 0
for s in graph.subjects(predicate=RDF.type, object=SKOS.Concept):
count += 1
print(f"\t- {s}")
if count >= 3:
break
# EXAMPLE Store 5: using a SPARQL endpoint that requires Basic HTTP authentication
# NOTE: this example won't run since the endpoint isn't live (or real)
sparql_store = SPARQLStore(
query_endpoint="http://fake-sparql-endpoint.com/repository/x",
auth=("my_username", "my_password"),
)
# do normal Graph things