 non-Python process buffers using the default (Emacs-supplied) process
 filter."
   (interactive "P")
-  (if (null py-which-shell)
-      (cond ((eq py-default-interpreter 'cpython)
-	     (setq py-which-shell py-python-command
-		   py-which-args py-python-command-args))
-	    ((eq py-default-interpreter 'jpython)
-	     (setq py-which-shell py-jpython-command
-		   py-which-args py-jpython-command-args))
-	    (t (error "Illegal value for `py-default-interpreter': %s"
-		      py-default-interpreter))))
   (let ((args py-which-args))
     (when (and argprompt
 	       (interactive-p)


(defun py-toggle-shells (arg)
  "Toggles between the CPython and JPython shells.
With positive argument ARG (interactively \\[universal-argument]),
uses the CPython shell, with negative ARG uses the JPython shell, and
with a zero argument, toggles the shell."
  (interactive "P")
  ;; default is to toggle
  (if (null arg)
      (setq arg 0))
  ;; toggle if zero
  (if (= arg 0)
      (if (string-equal py-which-bufname "Python")
	  (setq arg -1)
	(setq arg 1)))
  (let (msg)
    (cond
     ((< 0 arg)

`py-jpython-command-args' are consulted to determine the interpreter
and arguments to use.

Note that this variable is consulted only the first time that a Python
mode buffer is visited during an Emacs session.  After that, use
\\[py-toggle-shells] to change the interpreter shell."
  :type '(choice (const :tag "Python (a.k.a. CPython)" cpython)
		 (const :tag "JPython" jpython))
