how to bind custom commands to keys in existing mode map?

Question

I wrote some extra commands for Python mode: python-insert-quote and python-insert-double-quote. I want to have these commands be available in the minibuffer when python-mode is active. How can I add these custom functions into python-mode without write a new mode?

I was thinking it might be nice to keep these additional functions saved in ~/.emacs.d/lisp/extra-python.el

I'm not sure how hooks work or if this would be the right time to use hooks. When I look at hooks, It says that hooks are used to change the behavior of a mode, giving this example:

(add-hook 'text-mode-hook 'auto-fill-mode)

The example would seem antithetical to what I'm trying to do. I just what the functions to be callable form the mini-buffer only when in python-mode, not to be called when the mode is launched.

---

GNU Emacs 26.1

saved in ~/.emacs.d/lisp/extra-python.el

(defun python-insert-quote ()
  "Inesert python single quote"
  (interactive)
  (let ((myline (thing-at-point 'line)))
    (while (string-match "\\([^ ].*\\)" myline )
      ;; remove line
      (kill-whole-line)
      ;; add better line
      (insert (concat "'" (match-string 0 myline) "'" "
"))
      ;; fix indent
      (forward-line -1)
      (beginning-of-line)
      (indent-for-tab-command)
      (error ""))))         ;(break) the equivalent

(defun python-insert-double-quote ()
  "Inesert python double quote"
  (interactive)
  (let ((myline (thing-at-point 'line)))
    (while (string-match "\\([^ ].*\\)" myline )
      ;; remove line
      (kill-whole-line)
      ;; add better line
      (insert (concat "\"" (match-string 0 myline) "\"" "
"))
      ;; fix indent
      (forward-line -1)
      (beginning-of-line)
      (indent-for-tab-command)
      (error ""))))         ;(break) the equivalent

(provide 'extra-python)

saved in ~/.emacs.d/init.el

;; Add commands to python mode
(add-hook 'python-mode-hook (lambda ()
  (define-key python-mode-map [f6] 'python-insert-quote)
  (define-key python-mode-map [f5] 'python-insert-double-quote)))

Answer 1

The typical way this is done is by assigning the custom commands to keyboard shortcuts of a given major-mode; e.g.,

add to your Emacs init file

;; Add commands to python mode
(require 'extra-python)

and then either

(eval-after-load "python-mode" '(progn
  (define-key python-mode-map [f5] 'python-insert-quote)
  (define-key python-mode-map [f6] 'python-insert-double-quote))

or

(add-hook 'python-mode-hook (lambda ()
  (define-key python-mode-map [f5] 'python-insert-quote)
  (define-key python-mode-map [f6] 'python-insert-double-quote)))

One can store his/her custom commands wherever it makes sense in the opinion of the user. At the very bottom of extra-python.el, you can insert a statement (provide 'extra-python) and then ensure that the ~/.emacs.d/lisp/ directory has been added to the load-path.

If the function definitions have been loaded and are interactive (they are commands), a user can always type:

M-x NAME-OF-COMMAND