HTTP SPARQL server and client for twisted and rdflib

This library is for programs that use twisted for networking, use rdflib for RDF, and want to do sparql over http. It contains a client and a server, but you should be able to mix and match with other sparql clients and servers.

RemoteGraph twisted web client that talks to SPARQLResource (or other sparql-over-http servers)
⇑ HTTP ⇓
SPARQLResource twisted web resource that supports various GET/POST commands
Graph2 slightly different API for the rdflib graph class
ConjunctiveGraph (from rdflib)

There is also a LocalGraph class, which presents exactly the same API as RemoteGraph, but it talks to an in-process rdflib graph. This is convenient for testing your async RemoteGraph code without bothering to setup the http connection.

# this code will work whether graph is a RemoteGraph or a LocalGraph

    def method(self):
        d = graph.remoteLabel(subj)

    def withLabel(self, label):
        print label


Darcs source code repository

sparqlhttp-1.14.tar.gz (2014-11-10) add some compatibility with older rdflib; switch syncimport from pyxml to dateutil
sparqlhttp-1.13.tar.gz (2012-01-12) make dictquery.Graph2 be more compatible with the newer graph2.SyncGraph
sparqlhttp-1.12.tar.gz (2011-11-16) speed up parsing; a few other edge cases (full changelog)
sparqlhttp-1.11.tar.gz (2010-11-12) turn off the setuptools_trial dep (full changelog)
sparqlhttp-1.10.tar.gz (2010-07-13) some new methods: subgraphClear, subgraphStatements
sparqlhttp-1.9.tar.gz (2010-06-02) test version of my new API version (SyncGraph/AsyncGraph); server side is incomplete (full changelog)
sparqlhttp-1.5.tar.gz (2010-04-29) packaging; add some new sync and sesame variations (full changelog)
sparqlhttp-1.4.tar.gz (2010-03-20) minor packaging fixes (full changelog)
sparqlhttp-1.3.tar.gz (2009-10-12) changelog
sparqlhttp-1.2.tar.gz (2008-02-06) changelog
sparqlhttp-1.1.tar.gz (2007-08-07) changelog
sparqlhttp-1.0.tar.gz (2007-03-01)


Future plans


  1. Start a server, creating a new berkeleydb instance in ./db/
    ./sparqlserve --home db
    2007/01/22 00:58 -0700 [-] Log opened.
    2007/01/22 00:58 -0700 [-] twisted.web.server.Site starting on 9991
    2007/01/22 00:58 -0700 [-] Starting factory <twisted.web.server.Site instance at 0xb7646aac>
  2. In another shell, parse some NT and POST it to the server. The post will be to "/add?context=" with data consisting of NT statements. That part of my protocol is not part of any standard.
    ./graphimport hello.nt
    Server says:
    2007/01/22 01:14 -0700 [HTTPChannel,0,] - - [22/Jan/2007:08:14:08 +0000] "POST /add?context=http%3A// HTTP/1.0" 200 2 "-" "Twisted PageGetter"
  3. GET the query "SELECT ?s ?p ?o WHERE { ?s ?p ?o }" from the server. This uses the standard SPARQL query and results formats.
    Server says:
    2007/01/22 01:15 -0700 [HTTPChannel,1,] - - [22/Jan/2007:08:15:32 +0000] "GET /?query=SELECT%20%3Fs%20%3Fp%20%3Fo%20WHERE%20%7B%20%3Fs%20%3Fp%20%3Fo%20%7D HTTP/1.0" 200 617 "-" "Twisted PageGetter"
    Client says:
  4. Do an arbitrary query on the server.
    ./query "SELECT ?label WHERE { ?s <> ?label }"
    [{'label': rdflib.Literal('Hello',language=None,datatype=None)}]
  5. Check out the server diagnostics at http://localhost:9991/

    I deliberately made an error request to cause the the traceback below. The table at the bottom is really nice for large programs, since it shows what lines in your code made the various queries.

    sparqlhttp server status

    • 2 queries
    • Last error:
      SELECT ?broken { ?typo here }
      Traceback (most recent call last):
        File "sparqlhttp-1.0/sparqlhttp/", line 48, in getQuery
          results = self.graph.queryd(query)
        File "sparqlhttp-1.0/sparqlhttp/", line 80, in queryd
        File "/usr/lib/python2.4/site-packages/rdflib-2.3.3-py2.4-linux-i686.egg/rdflib/", line 644, in query
          return plugin.get('SPARQLQueryResult',QueryResult)(p.query(strOrQuery, initBindings, initNs, DEBUG))
        File "/usr/lib/python2.4/site-packages/rdflib-2.3.3-py2.4-linux-i686.egg/rdflib/sparql/bison/", line 26, in query
          strOrQuery = Parse(strOrQuery, DEBUG)
        File "/usr/lib/python2.4/site-packages/rdflib-2.3.3-py2.4-linux-i686.egg/rdflib/sparql/bison/", line 16, in Parse
          return p.parse(unicode(query,'utf-8'))
      SyntaxError: lexical error at line 1, column 30: no action found for 'here }'
    • Last query:
      SELECT ?broken { ?typo here }
      Again, as one line:
      SELECT ?broken { ?typo here }
    • All query types, by total time spent
      total secs (per)countquery (with sample initBindings)boundavg rowssources
      0.01 (0.0110)1
      SELECT ?s ?p ?o WHERE { ?s ?p ?o }
  6. Try running the tests. They use twisted trial and they run from the test directory:
    cd test
    trial    # all these should work
    trial   # this one might not do as well