ATTENTION: you probably don't need this plugin! See Why you may not need this plugin.
vim-yapf is a Vim plugin that applies yapf to your current file.
yapf automatically formats Python code, based on improved syntax styles.
yapf can be installed either with pip:
pip install yapf
or by installing with conda (OSX and linux64 only) with my binstar channel:
conda install -c https://conda.binstar.org/srwalker101 yapf
Either use a plugin manager and add Plug[in] 'mindriot101/vim-yapf' to your vimrc, or use pathogen.
The plugin does not create any bindings by default, this is left up to the user. An example could be:
:nnoremap <leader>y :call Yapf()<cr>
or
:nnoremap <leader>y :Yapf<cr>
call function
:Yapf
with arguments
:Yapf --style google
or
:call Yapf(" --style pep8")
The yapf style can be globally set, in your vimrc:
let g:yapf_style = "google"
or
let g:yapf_style = "pep8"
The plugin itself is very simple. It handles user options granted, but at its core it uses ex commands to perform its magic. yapf behaves like a good unix command: it takes text on stdin and spits the altered result to stdout, which is exactly what vim expects.
At its core, this plugin runs the ex command:
0,$!yapf
This pipes the range 0,$ i.e. the whole file through a shell command yapf and replaces the range with the altered result.
Instead of installing this plugin, one could add a mapping e.g.:
autocmd FileType python nnoremap <leader>y :0,$!yapf<Cr><C-o>
Alternatively yapf can be configured to run on save:
autocmd BufWritePre *.py 0,$!yapf
Warning: yapf errors will overwrite your buffer. If you typed :w, you can
type :undo to get your old buffer back. If you typed :ZZ, there is no way
to get your old buffer back. Use this solution
to automatically make backups, so you don't lose too many edits.
Alternatively yapf could be set as the formatprg for the python filetype, and reformatting can be performed with the gq{motion} operator (e.g. with visual selection) to reformat a part of the file.
Alternatively alternatively yapf could be set as the equalprg:
setlocal equalprg=yapf
and reformat the whole file with gg=G or a single line with =.