For those wondering, us Emacs creatures use Rope + ropemacs + rope-mode to achieve the same thing. Vim has access to the same tooling more or less.
From the article: > Rope-based completion was always unreliable, slow or both. I haven't used rope. Is the author wrong about this?
I've used PyCharm before, IME people that complain about Rope autocompletion aren't adding the virtualenv to their Rope search paths.
As for slowness? only on init. After that, it's as close to instantaneous as it gets.