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"""
A simple example showing how to use a Sleepycat store to do on-disk
persistence.
"""
from rdflib import ConjunctiveGraph, Namespace, Literal
from rdflib.store import NO_STORE, VALID_STORE
from tempfile import mktemp
if __name__ == "__main__":
path = mktemp()
# Open previously created store, or create it if it doesn't exist yet
graph = ConjunctiveGraph("Sleepycat")
rt = graph.open(path, create=False)
if rt == NO_STORE:
# There is no underlying Sleepycat infrastructure, so create it
graph.open(path, create=True)
else:
assert rt == VALID_STORE, "The underlying store is corrupt"
print("Triples in graph before add: ", len(graph))
# Now we'll add some triples to the graph & commit the changes
rdflib = Namespace("http://rdflib.net/test/")
graph.bind("test", "http://rdflib.net/test/")
graph.add((rdflib["pic:1"], rdflib.name, Literal("Jane & Bob")))
graph.add((rdflib["pic:2"], rdflib.name, Literal("Squirrel in Tree")))
print("Triples in graph after add: ", len(graph))
# display the graph in RDF/XML
print(graph.serialize(format="n3"))
# close when done, otherwise sleepycat will leak lock entries.
graph.close()
graph = None
# reopen the graph
graph = ConjunctiveGraph("Sleepycat")
graph.open(path, create=False)
print("Triples still in graph: ", len(graph))
graph.close()
# Clean up the temp folder to remove the Sleepycat database files...
import os
for f in os.listdir(path):
os.unlink(path + "/" + f)
os.rmdir(path)
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