Fix for `M-x elpy-doc`

elpy-fixes.el

(use-package elpy
  :ensure
  :demand flycheck
  :init (elpy-enable)
  :config
  (advice-add 'elpy-doc :around #'rk/elpy-doc-fallback-to-help))

;; help from python, see https://github.com/jorgenschaefer/elpy/pull/1509 and
;; https://github.com/jorgenschaefer/elpy/issues/1507
(defun rk/elpy-doc-get-docstring-from-shell ()
  "Return the docstring for the symbol at point using the shell."
  (when (elpy-shell--check-if-shell-available)
    (let* ((process (python-shell-get-process))
           (symbol (elpy-doc--symbol-at-point))
           (docstring
            (when symbol
              (python-shell-send-string-no-output
               (format "import pydoc, io\noutput = io.StringIO()\nh = pydoc.Helper(output=output)\nh.help(%s)\nprint(output.getvalue())" symbol)
               process))))
      (unless (or (not docstring)
                  (zerop (length docstring))
                  (string-match "Traceback (most recent call last):"
                                docstring)
                  (string-match "No Python documentation found for"
                                docstring))
        ;; Remove potential warnings in the output
        (substring docstring (string-match "^Help on " docstring))))))

(defun rk/elpy-doc-fallback-to-help (orig-fun &rest args)
  (unwind-protect
      (progn
        (funcall orig-fun))
    (when-let ((doc (rk/elpy-doc-get-docstring-from-shell)))
      (elpy-doc--show doc))))