As per this commit for the current Spyder developpement version
https://bitbucket.org/spyder-ide/spyderlib/commits/49c79faa7439af85e8cff1d5d0727a280e487a07
(progress towards 2.3.2), it seems that Rope-py3k 0.9.4-1 was not properly supported(patched) in Spyder 2.3.1. Next version of Spyder, which should solve the issue, is due this month. In the meantime, we might, however, want to cherry pick this commit in order to restore code completion in Spyder?