remove unused 'pk' slot in node infos (only copies node id)

graph/bridgeness.py

@@ -13,7 +13,6 @@ def filterByBridgeness(G,partition,ids,weight,bridgeness,type,field1,field2):
         nodesB_dict = {}
         for node_id in G.nodes():
             #node,type(labels[node])
-            G.node[node_id]['pk']           = ids[node_id][1]
             nodesB_dict [ ids[node_id][1] ] = True
             # TODO the query below is not optimized (do it do_distance).
             the_label = session.query(Ngram.terms).filter(Ngram.id==node_id).first()