from rdflib import Graph, Namespace, Literal

# Define some namespaces

dc = Namespace("http://purl.org/dc/elements/1.1/")
census = Namespace("tag:govshare.info,2005:rdf/census/")

# Create a store to hold RDF data

store = Graph();

# Load the N3 file with the states data

store.parse("states.n3", None, 'n3');

# Get the entity representing Pennsylvania.  'None' is like a wildcard,
# so we're getting the thing that matches the statement:
#   ____ dc:title "Pennsylvania"

pennsylvania = store.value(None, dc["title"], Literal("Pennsylvania"));

# Get its population.  This time we're getting the thing that matches:
#  pennsylvania census:population _____

population = store.value(pennsylvania, census["population"], None);
   
print population