RDFlib

My command line OWL processor

With most of the credit going to to Ivan Herman.

I recently asked on Twitter about the availability of command line OWL processors. I got some leads, but most would have required a little coding or integration work on my part. I decided that a small project that I did with the OWL-RL Python library a few years ago gave me a head start on just creating my own OWL command line processor in Python. It was pretty easy.

Pipelining SPARQL queries in memory with the rdflib Python library

Using retrieved data to make more queries.

Last month in Dividing and conquering SPARQL endpoint retrieval I described how you can avoid timeouts for certain kinds of SPARQL endpoint queries by first querying for the resources that you want to know about and then querying for more data about those resources a subset at a time using the VALUES keyword. (The example query retrieved data, including the latitude and longitude, about points within a specified city.) I built my demo with some shell scripts, some Perl scripts, and a bit of spit…

Note: I wrote this blog entry to accompany the IBM Data Magazine piece mentioned in the first paragraph, so for people following the link from there this goes into a little more detail on what RDF, triples, and SPARQL are than I normally would on this blog. I hope that readers already familiar with these standards will find the parts about doing the inferencing on a Hadoop cluster interesting.