I’ve been meaning to blog about this for some time, so I suppose now
is as good an opportunity as any. This is going to be a very “stream
of consciousness”-esque posting, so bear with me. Some of these are
things that have radically changed the way I use emacs. Others are
minor changes that I like. Feel free to pick and choose from them.
I’ll assume you’re running Ubuntu. Also, not all of these are Python
specific. But I feel that they will be useful to most Python
programmers who use emacs.
I should also note that (like most emacs users), most of these things
are tricks that I’ve picked up from various sources along the way. If
you wrote something that I put in here, thanks!
Ropemacs is among the tools I love the most and hate the most. When
it works, it opens up a new world of automated refactorings for you.
But it seems to be a bit buggy at times. That said, setting it up is
really easy. Firstly, you need to have ropemacs installed. This is
sudo apt-get install python-ropemacs
After that, just a couple of lines of elisp in your .emacs file and
you’re good to go!
(require 'pymacs) (pymacs-load "ropemacs" "rope-") (setq ropemacs-enable-autoimport t)
(require 'anything-config) (require 'anything-match-plugin) (global-set-key "\C-ca" 'anything) (global-set-key "\C-ce" 'anything-for-files)
Then, prepare to spend a lot less time searching for files!
Line number mode
When you’re pair programming, nothing is more helpful than being able
to direct people to a certain line of code. This lets you spend less
time saying “hey, see that over there? It’s about 3 lines up. No,
too far! go down another two lines.” Installing this is really easy.
You just need linum.el and two lines of elisp:
(require 'linum) (global-linum-mode 1)
Flymake through pyflakes
In case you miss the automatic error highlighting of the Visual Studio
world, you should realize that emacs has a similar system built-in.
It’s called flymake. And you can make it work with Python as well. I
personally prefer to use pyflakes for this. All that’s needed is
sudo apt-get install pyflakes
…and some elisp:
(when (load "flymake" t) (defun flymake-pyflakes-init () (let* ((temp-file (flymake-init-create-temp-buffer-copy 'flymake-create-temp-inplace)) (local-file (file-relative-name temp-file (file-name-directory buffer-file-name)))) (list "pyflakes" (list local-file)))) (add-to-list 'flymake-allowed-file-name-masks '("\\.py\\'" flymake-pyflakes-init)))
How many __init__.py buffers do you have open at this moment? If
you’re using emacs for Python programming, probably a lot. This is
where emacs’s uniquify functionality is useful. It gives you a more
useful name for your buffers other than just appending a number at the
end. I have mine use the reverse of the directory. For instance, if
I have foo/__init__.py and bar/__init__.py open, they will be named
__init__.py/foo and __init__.py/bar respectively.
You just need this in your .emacs:
(setq uniquify-buffer-name-style 'reverse) (setq uniquify-separator "/") (setq uniquify-after-kill-buffer-p t) ; rename after killing uniquified (setq uniquify-ignore-buffers-re "^\\*") ; don't muck with special buffers (or Gnus mail buffers)
To be totally honest with you, I haven’t used the built-in emacs mode
for python. I just installed python-mode because I was told it was
better. What I can tell you is that there is an occasional plugin
that requires python-mode. Installing it is easy. Just install
sudo apt-get install python-mode
And add some elisp:
(autoload 'python-mode "python-mode" "Python Mode." t) (add-to-list 'auto-mode-alist '("\\.py\\'" . python-mode)) (add-to-list 'interpreter-mode-alist '("python" . python-mode))
Pylookup is useful for those moments when you find yourself asking
something like “Is join in os or os.path?” Unfortunately, the setup
can be complex, but well worth it. There are instructions here.