Check whether GBQ Job is finished

jobComplete can be False in query_reply. Simply checking for the existence of the field isn't enough, as a False value will cause a KeyError when checking for query_reply['totalRows']
usually I would prefer `not query_reply['jobComplete']` to `query_reply['jobComplete'] is False`

you could also consolidate these with `while(not query_reply.get('jobComplete', False))`