In the most recent version of Ureka (1.4), the function .has_key() has been dropped. Consequently, the DRP code doesn't work on this version of Ureka (or any newer version of ipython for that matter) anymore. I found that changing, say, "something.has_key(key)" to "key in something" fixed the problem. You might want to implement that in the next version.
Regards,
Kaew Tinyanont