python - How to change `rdf:description` namespace using rdflib? -

i'm dabbling in managing rdf python using rdflib, , ran across page (http://www.obitko.com/tutorials/ontologies-semantic-web/rdf-graph-and-syntax.html) outlines rdf syntax. in it, rdf example following:

<rdf:rdf     xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"     xmlns:foaf="http://xmlns.com/foaf/0.1/"     xmlns="http://www.example.org/~joe/contact.rdf#">   <foaf:person rdf:about="http://www.example.org/~joe/contact.rdf#joesmith">     <foaf:mbox rdf:resource="mailto:joe.smith@example.org"/>     <foaf:homepage rdf:resource="http://www.example.org/~joe/"/>     <foaf:family_name>smith</foaf:family_name>     <foaf:givenname>joe</foaf:givenname>   </foaf:person> </rdf:rdf> 

in here, code rdf object denotes foaf:person, in other instances i've seen, line rdf:description. i'm curious whether example correct, , if difference between re-definition , standard rdf:description syntax. furthermore, how 1 implement namespace in python using rdflib? i've got following code, creates example rdf, results in rdf:description instead of foaf:person line:

import rdflib rd rdflib.namespace import foaf  joe = rd.uriref("http://www.example.org/~joe/contact.rdf#joesmith") joeemail = rd.uriref('mailto:joe.smith@example.org') joehome = rd.uriref('http://www.example.org/~joe/') joefamily = rd.literal('smith') joename = rd.literal('joe')  g = rd.graph()  g.bind('foaf', foaf, false)  g.add((joe, foaf.mbox, joeemail)) g.add((joe, foaf.homepage, joehome)) g.add((joe, foaf.family_name, joefamily)) g.add((joe, foaf.givenname, joename))  fp = open('outfile.rdf','wb') fp.write(g.serialize(format='xml')) fp.close() 

having <foo:bar> element opposed <rdf:description> element syntactic compression used when rdf:type declared subject.

both examples correct version rdf:description either missing rdf:type triple or serialised has chosen not use specific syntactic compression. in general property of rdf/xml, there lots of different ways serialise same graph , given same set of triples different tools may produce different equivalent serialisations.

so in order produce equivalent rdf/xml need add additional rdf:type triple:

from rdflib.namespace import rdf g.add((joe, rdf.type, foaf.person));