Redefine major mode prefix key in Emacs

Question

I've been trying teach myself emacs, and because I am using dvorak, I foolishly rebound C-c to a movement key and got used to it. Now i'm actually starting to do some programming with it, and I loaded up a python file and noticed that C-c is the prefix to all the special commands in python-mode.

Can I rebind the prefix key and change all python commands in one swoop in my init.el file? If not, should I rebind all the python commands individually?

Answer 1

If you want Ctrl+C to act as left and F12 to act as C-c:

(define-key key-translation-map [f12] "\C-c")
(define-key key-translation-map "\C-c" [left])

Note that this will also influence multi-key bindings, e.g. you now need to type Ctrl+X F12 to exit Emacs. The flip side of this coin is that C-c C-c is typed as F12 F12.

Answer 2

If you look at the source code for python.el, you'll see that the commands were added individually using the full specification, e.g. (define-key map "\C-c\C-r" 'python-send-region).

So, you're going to have to redo them all yourself. That said it is pretty straight-forward. From your comment, you want to change the prefix key to be C-', and the trick to getting escaping right is to not use escapes at all, but instead to use the macro kbd (documentation link).

With that, you can update the mode-map definition to be:

(defvar python-mode-map
  (let ((map (make-sparse-keymap)))
    ;; Mostly taken from python-mode.el.
    (define-key map ":" 'python-electric-colon)
    (define-key map "\177" 'python-backspace)
    (define-key map (kbd "C-' <") 'python-shift-left)
    (define-key map (kbd "C-' >") 'python-shift-right)
    (define-key map (kbd "C-' C-k") 'python-mark-block)
    (define-key map (kbd "C-' C-d") 'python-pdbtrack-toggle-stack-tracking)
    (define-key map (kbd "C-' C-n") 'python-next-statement)
    (define-key map (kbd "C-' C-p") 'python-previous-statement)
    (define-key map (kbd "C-' C-u") 'python-beginning-of-block)
    (define-key map (kbd "C-' C-f") 'python-describe-symbol)
    (define-key map (kbd "C-' C-w") 'python-check)
    (define-key map (kbd "C-' C-v") 'python-check) ; a la sgml-mode
    (define-key map (kbd "C-' C-s") 'python-send-string)
    (define-key map (kbd "C-\\ M-x") 'python-send-defun)
    (define-key map (kbd "C-' C-r") 'python-send-region)
    (define-key map (kbd "C-' M-r") 'python-send-region-and-go)
    (define-key map (kbd "C-' C-c") 'python-send-buffer)
    (define-key map (kbd "C-' C-z") 'python-switch-to-python)
    (define-key map (kbd "C-' C-m") 'python-load-file)
    (define-key map (kbd "C-' C-l") 'python-load-file) ; a la cmuscheme
    (substitute-key-definition 'complete-symbol 'symbol-complete
                               map global-map)
    (define-key map (kbd "C-' C-i") 'python-find-imports)
    (define-key map (kbd "C-' C-t") 'python-expand-template)
    (easy-menu-define python-menu map "Python Mode menu"
      `("Python"
        :help "Python-specific Features"
        ["Shift region left" python-shift-left :active mark-active
         :help "Shift by a single indentation step"]
        ["Shift region right" python-shift-right :active mark-active
         :help "Shift by a single indentation step"]
        "-"
        ["Mark block" python-mark-block
         :help "Mark innermost block around point"]
        ["Mark def/class" mark-defun
         :help "Mark innermost definition around point"]
        "-"
        ["Start of block" python-beginning-of-block
         :help "Go to start of innermost definition around point"]
        ["End of block" python-end-of-block
         :help "Go to end of innermost definition around point"]
        ["Start of def/class" beginning-of-defun
         :help "Go to start of innermost definition around point"]
        ["End of def/class" end-of-defun
         :help "Go to end of innermost definition around point"]
        "-"
        ("Templates..."
         :help "Expand templates for compound statements"
         :filter (lambda (&rest junk)
                   (abbrev-table-menu python-mode-abbrev-table)))
        "-"
        ["Start interpreter" python-shell
         :help "Run `inferior' Python in separate buffer"]
        ["Import/reload file" python-load-file
         :help "Load into inferior Python session"]
        ["Eval buffer" python-send-buffer
         :help "Evaluate buffer en bloc in inferior Python session"]
        ["Eval region" python-send-region :active mark-active
         :help "Evaluate region en bloc in inferior Python session"]
        ["Eval def/class" python-send-defun
         :help "Evaluate current definition in inferior Python session"]
        ["Switch to interpreter" python-switch-to-python
         :help "Switch to inferior Python buffer"]
        ["Set default process" python-set-proc
         :help "Make buffer's inferior process the default"
         :active (buffer-live-p python-buffer)]
        ["Check file" python-check :help "Run pychecker"]
        ["Debugger" pdb :help "Run pdb under GUD"]
        "-"
        ["Help on symbol" python-describe-symbol
         :help "Use pydoc on symbol at point"]
        ["Complete symbol" symbol-complete
         :help "Complete (qualified) symbol before point"]
        ["Find function" python-find-function
         :help "Try to find source definition of function at point"]
        ["Update imports" python-find-imports
         :help "Update list of top-level imports for completion"]))
    map))