init.el

(defun py-doc-exec ()
  (interactive)
  (save-current-buffer
    (let ((symbol
           (with-syntax-table python-dotty-syntax-table (current-word)))
          (tmpbuf (get-buffer-create "*py-doc-popup*"))
          (enable-recursive-minibuffers t))
      (if (equal symbol "") (error "No symbol"))
      (set-buffer "*py-doc-popup*")
      (comint-redirect-send-command-to-process
       (format "emacs.ehelp(%S, %s)"
               symbol python-imports) "*py-doc-popup*" (python-proc) nil t))))

(require 'deferred)

(defun py-doc-popup ()
  "Get help() for object at point, and display it in a popup."
  ;; Note that we do this in the inferior process, not a separate one, to
  ;; ensure the environment is appropriate.
  (interactive)
  (py-doc-exec)
  (deferred:$
    (deferred:wait 100)
    (deferred:nextc it
      (lambda (x)
        (let ((curbuf (current-buffer)))
          (set-buffer "*py-doc-popup*")
          (let ((bs (buffer-string)))
            (set-buffer curbuf)
            (popup-tip bs))
          (kill-buffer "*py-doc-popup*"))))))