在Emacs中复制和粘贴Python函数

Question

I have a program that looks something like (this is a silly example to illustrate my point, what it does is not very important)

count = 0

def average(search_term):
    average = 0
    page = 0
    current = download(search_term, page)
    while current:
        def add_up(downloaded):
            results = downloaded.body.get_results()
            count += len(results)
            return sum(result.score for result in results)
        total = average*count
        total += add_up(current)
        average = total/count
        print('Average so far: {:2f}'.format(average))
        page += 1
        current = download(search_term, page)

If I have the cursor on any of the lines 8–11 and press a key combination I want Emacs to copy or kill the add_up function, and then I want to move the cursor to line 2 and press a key combination and paste the function there, with the correct level of indentation for the context it is pasted in.

Is this possible, and if so, how would I do that?

Answer 1

With python-mode.el py-kill-def and yank would do the job. However, there are some restrictions. py-kill-def must be called from inside def in question. So needs to go upward from line 11 first. Also indenting after insert poses some problems: as indent is syntax, sometimes Emacs can't know which indentation is wanted. In example below have an indent of 4 first and of 8 in add_up probably is not wanted - however it's legal code. After indenting first line in body of add_up , py-indent-and-forward should be convenient for the remaining.

def average(search_term):
    average = 0
    def add_up(downloaded):
            results = downloaded.body.get_results()
            count += len(results)
            return sum(result.score for result in results)
    page = 0
    current = download(search_term, page)
    while current:

        total = average*count
        total += add_up(current)
        average = total/count
        print('Average so far: {:2f}'.format(average))
        page += 1
        current = download(search_term, page)

Answer 2

For this type of thing I usually use expand-region , which I choose to bind to C-= .

Using your example I can select the add_up() function by pressing C-= once, kill the region normally ( Ck ), move to line 2, and yank as usual ( Cy ).

Depending on what else you have configured for Python you may have to clean up some whitespace, or it may get cleaned up for you. For example, aggressive-indent would be helpful.

One manual option would be to reindent the pasted code with something like Cx Cx M-\\ .

Answer 3

I've been using smart-shift (available in Melpa) for this sort of thing. global-smart-shift-mode to enable (beware, it binds keys). Select the block you want to move (I'd use expand-region like Chris), and the default keybind CSc <arrow> starts moving it. Once you're shifting, the arrows (without CSc ) shift further. Horizontal shifts use the major mode's indent offset ( python-indent-offset for python.el).