I fount the issue - there were old py files generated by the py2 pike - once I deleted them and the py3 pike regenerated them all was well.
I have a script I am porting from 2.7 to 3.5 and it's failing here: from pyke import knowledge_engine vasculopathy_engine = knowledge_engine.engine((rule_base_source_folder, (compiled_rule_base_folder))) with vasculopathy_engine.prove_goal(...) as presentationGen: for vals, plan in presentationGen: AttributeError: module 'itertools' has no attribute 'imap'