Python Secret Weblog for 2008 August 1 (entry 0)

(3) Fri Aug 01 2008 16:53 megrok.rdf finally checked in:

Jasper Op de Coul and I worked on megrok.rdf during the post-europython Grok sprint a few weeks ago. We had a few logistical problems concerning access to svn.zope.org, but yesterday Jasper finally managed to check in megrok.rdf:

http://svn.zope.org/megrok.rdf/trunk/

megrok.rdf is far from finished, and should be classified as a prototype. It has me excited for two reasons:

• if people were to hack on this I think Grok could quickly grow first-class RDF support without tremendous effort. What megrok.rdf can do for you is represent RDF subjects as models. These can then get views and adapters and such. RDF predicates can show up as object relations. These relations can be made to be traversable using grok.traversable().
• the way megrok.rdf works is quite similar to megrok.rdb, Grok's SQLAlchemy integration. This is not a surprise, as megrok.rdf's design is heavily influenced by my experiences with megrok.rdb. It still helps validate to me that Grok's way of exposing models makes a lot sense and is flexible. Grok has ZODB-backed Models and Containers, but it also has RDB backed Models and Containers and now, at least experimentally, RDF backed versions of the same.

A lot of work remains to be done. One thing we should do is to actually start documentation/doctests to solidify the approach. The way an RDF database is accessed (and integrated with Zope's transaction machinery) also needs attention.

I hope we can get some help from people interested in RDF. If people are interested, please join us at grok-dev.

---

Comments:

Posted by Robert at Fri Aug 01 2008 19:02

Do you think that people are not trying out Zope/Grok because it doesn't support Python 2.5? It seems all the new distros now have the 2.5 series in them. I have hesitated trying it all out as well because of its dependence on 2.4 but I would love to try it.

Not disparaging, just commenting.

Posted by Danny Navarro at Fri Aug 01 2008 20:21

That's great news.

Now I don't have enough time and expertise, but I'm definitely interested in this project for the future.

In bioinformatics semantic web is becoming a hot topic, with Apache Jena as the main web framework written in Java. I haven't seen any Python web framework which supports directly RDF.

Having support for SPARQL and OWL would be great.

Posted by Martijn Faassen at Fri Aug 01 2008 21:28

Robert, it's true that Python 2.5 support should be on our agenda. People have reported success on Python 2.5 with the current releases (and Zope 3.4.x), and in theory the packages underlying Grok should support it, but we should officially support Python 2.5.

The current trunk of Grok does run all its tests on Python 2.5 already (we fixed an very small issue which caused one test to fail a while back).