I'm attempting my first modification of emacs. I recorded a little keyboard macro and had emacs spit it out as elisp, resulting in:

(setq add-docstring
    "\C-rdef\C-n\C-a\C-m\C-p\C-i\C-u6\"\C-u3\C-b")
(global-set-key "\C-c\C-d" 'add-docstring)

Searching the emacs reference, though, revealed that C-c C-d is already bound in diff mode. I don't plan on using diff mode, but the future is unknowable and I'd like to not lay a trap for myself. So I'd like this keybinding to only operate in python mode, where it tries to help me add docstrings.

In my /usr/share/emacs/23.whatever/list/progmodes, I found python.elc and python.el.gz. I unzipped python.el.gz and got a readable version of the elisp file. Now, though, the documentation becomes opaque to me.

How can I add my key binding to the python mode, instead of globally?

Is it possible, for bonus points, to apply the changes to python mode without restarting emacs or closing open files? It's the self-modifying editor, I figure there's a good chance that it's possible.