anchor.diff:  
   (defun get-repl-buffer ()
     (let ((buffer (make-buffer "*python*")))
  -    (change-buffer-mode buffer 'run-python-mode)
  +    (unless (eq (buffer-major-mode buffer) 'run-python-mode)
  +      (change-buffer-mode buffer 'run-python-mode))
       buffer))
   
   (defun output-callback (string)
  
positive.code: 
  (defun run-python-internal ()
    (unless (alive-process-p)
      (setf *process*
            (lem-process:run-process "python"
                                     :name "run-python"
                                     :output-callback 'output-callback))))
  
  (define-command python-eval-region (start end) ("r")
    (when (alive-process-p)
      (lem-process:process-send-input *process* (points-to-string start end))))
  
  (define-command run-python () ()
    (run-python-internal))
  
negative.code: 
  (defun execute-input (point string)
    (declare (ignore point))
    (unless (alive-process-p)
      (editor-error "Python process doesn't exist."))
    (lem-process:process-send-input *process*
                                    (concatenate 'string string (string #\newline))))
  
  