用于Python的Emacs批量缩进

Question

Working with Python in Emacs if I want to add a try/except to a block of code, I often find that I am having to indent the whole block, line by line. In Emacs, how do you indent the whole block at once.

I am not an experienced Emacs user, but just find it is the best tool for working through ssh. I am using Emacs on the command line(Ubuntu), not as a gui, if that makes any difference.

Answer 1

If you are programming Python using Emacs, then you should probably be using python-mode. With python-mode, after marking the block of code,

Cc > or Cc Cl shifts the region 4 spaces to the right

Cc < or Cc Cr shifts the region 4 spaces to the left

If you need to shift code by two levels of indention, or some arbitary amount you can prefix the command with an argument:

Cu 8 Cc > shifts the region 8 spaces to the right

Cu 8 Cc < shifts the region 8 spaces to the left

Another alternative is to use Mx indent-rigidly which is bound to Cx TAB :

Cu 8 Cx TAB shifts the region 8 spaces to the right

Cu -8 Cx TAB shifts the region 8 spaces to the left

Also useful are the rectangle commands that operate on rectangles of text instead of lines of text.

For example, after marking a rectangular region,

Cx ro inserts blank space to fill the rectangular region (effectively shifting code to the right)

Cx rk kills the rectangular region (effectively shifting code to the left)

Cx rt prompts for a string to replace the rectangle with. Entering Cu 8 <space> will then enter 8 spaces.

PS. With Ubuntu, to make python-mode the default mode for all .py files, simply install the python-mode package.

Answer 2

In addition to indent-region , which is mapped to CM-\\ by default, the rectangle edit commands are very useful for Python. Mark a region as normal, then:

• Cx rt ( string-rectangle ): will prompt you for characters you'd like to insert into each line; great for inserting a certain number of spaces
• Cx rk ( kill-rectangle ): remove a rectangle region; great for removing indentation

You can also Cx ry ( yank-rectangle ), but that's only rarely useful.

Answer 3

映射到CM-\\ indent-region应该可以解决问题。

Answer 4

I've been using this function to handle my indenting and unindenting:

(defun unindent-dwim (&optional count-arg)
  "Keeps relative spacing in the region.  Unindents to the next multiple of the current tab-width"
  (interactive)
  (let ((deactivate-mark nil)
        (beg (or (and mark-active (region-beginning)) (line-beginning-position)))
        (end (or (and mark-active (region-end)) (line-end-position)))
        (min-indentation)
        (count (or count-arg 1)))
    (save-excursion
      (goto-char beg)
      (while (< (point) end)
        (add-to-list 'min-indentation (current-indentation))
        (forward-line)))
    (if (< 0 count)
        (if (not (< 0 (apply 'min min-indentation)))
            (error "Can't indent any more.  Try `indent-rigidly` with a negative arg.")))
    (if (> 0 count)
        (indent-rigidly beg end (* (- 0 tab-width) count))
      (let (
            (indent-amount
             (apply 'min (mapcar (lambda (x) (- 0 (mod x tab-width))) min-indentation))))
        (indent-rigidly beg end (or
                                 (and (< indent-amount 0) indent-amount)
                                 (* (or count 1) (- 0 tab-width))))))))

And then I assign it to a keyboard shortcut:

(global-set-key (kbd "s-[") 'unindent-dwim)
(global-set-key (kbd "s-]") (lambda () (interactive) (unindent-dwim -1)))

Answer 5

I'm an Emacs newb, so this answer it probably bordering on useless.

None of the answers mentioned so far cover re-indentation of literals like dict or list . Eg Mx indent-region or Mx python-indent-shift-right and company aren't going to help if you've cut-and-pasted the following literal and need it to be re-indented sensibly:

    foo = {
  'bar' : [
     1,
    2,
        3 ],
      'baz' : {
     'asdf' : {
        'banana' : 1,
        'apple' : 2 } } }

It feels like Mx indent-region should do something sensibly in python-mode , but that's not (yet) the case.

For the specific case where your literals are bracketed, using TAB on the lines in question gets what you want (because whitespace doesn't play a role).

So what I've been doing in such cases is quickly recording a keyboard macro like <f3> Cn TAB <f4> as in F3, Ctrl-n (or down arrow), TAB, F4, and then using F4 repeatedly to apply the macro can save a couple of keystrokes. Or you can do Cu 10 Cx e to apply it 10 times.

(I know it doesn't sound like much, but try re-indenting 100 lines of garbage literal without missing down-arrow, and then having to go up 5 lines and repeat things ;) ).

Answer 6

I use the following snippet. On tab when the selection is inactive, it indents the current line (as it normally does); when the selection is inactive, it indents the whole region to the right.

(defun my-python-tab-command (&optional _)
  "If the region is active, shift to the right; otherwise, indent current line."
  (interactive)
  (if (not (region-active-p))
      (indent-for-tab-command)
    (let ((lo (min (region-beginning) (region-end)))
          (hi (max (region-beginning) (region-end))))
      (goto-char lo)
      (beginning-of-line)
      (set-mark (point))
      (goto-char hi)
      (end-of-line)
      (python-indent-shift-right (mark) (point)))))
(define-key python-mode-map [remap indent-for-tab-command] 'my-python-tab-command)

Answer 7

Do indentation interactively.

1. Select the region to be indented.
2. Cx TAB .
3. Use arrows ( <- and -> ) to indent interactively.
4. Press Esc three times when you are done with the required indentation.

Copied from my post in: Indent several lines in Emacs

Answer 8

I do something like this universally

;; intent whole buffer 
(defun iwb ()
  "indent whole buffer"
  (interactive)
  ;;(delete-trailing-whitespace)
  (indent-region (point-min) (point-max) nil)
  (untabify (point-min) (point-max)))