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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, 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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