What is the recommended way to use Vim folding for Python code

Paul_D_Eden_3045 0
Viewed 56804

I am interested in enabling code folding in Vim for Python code. I have noticed multiple ways to do so.

Does anyone have a preferred way to do Python code folding in Vim? I.e,

  • Do you have a particular Vim plugin that you use and like?
  • Do you use manual folding or do you place markers in comments?
  • Any other recommended ways to do code folding for Python in Vim?
folding vim python
12 Answers

Personally I can't convince myself to litter my code with the markers. I've become pretty used to (and efficient) at using indent-folding. Together with my mapping of space bar (see below) to open/close folds and the zR and zM commands, I'm right at home. Perfect for Python!

set foldmethod=indent
nnoremap <space> za
vnoremap <space> zf
user_238400

I use this syntax file for Python. It sets the folding method to syntax and folds all classes and functions, but nothing else.

Admin1

Python is well suited for folding on indent, bit for writing my own code I use markers as they can crunch a document down the way you want it and can serve as a kind of a table of contents. I have this in my vimrc to flip between the two when I'm viewing someone elses code. 

#Toggle fold methods \fo
let g:FoldMethod = 0
map <leader>fo :call ToggleFold()<cr>
fun! ToggleFold()
    if g:FoldMethod == 0
        exe 'set foldmethod=indent'
        let g:FoldMethod = 1
    else
        exe 'set foldmethod=marker'
        let g:FoldMethod = 0
    endif
endfun
#Add markers (trigger on class Foo line)
nnoremap ,f2 ^wywO#<c-r>0 {{{2<esc>
nnoremap ,f3 ^wywO#<c-r>0 {{{3<esc> 
nnoremap ,f4 ^wywO#<c-r>0 {{{4<esc>
nnoremap ,f1 ^wywO#<c-r>0 {{{1<esc>
Admin1
user_409060
user_220350

In your .vimrc:

set foldmethod=indent
set shiftwidth=4

Then zM to mask all zR to expand all. I also added:

nnoremap <space> za
vnoremap <space> zf
map z1  :set foldlevel=0<CR><Esc>
map z2  :set foldlevel=1<CR><Esc>
map z3  :set foldlevel=2<CR><Esc>
map z4  :set foldlevel=3<CR><Esc>
map z5  :set foldlevel=4<CR><Esc>
map z6  :set foldlevel=5<CR><Esc>
map z7  :set foldlevel=6<CR><Esc>
map z8  :set foldlevel=7<CR><Esc>
map z9  :set foldlevel=8<CR><Esc>

So you can z1 and z2 to unindent little by little.

user_25448730

The Python source comes with a vim syntax plugin along with a custom vimrc file. Check the python FAQ on vim

ONODEVO_404400

I really like this little vim script i wrote for .vimrc. It maps alt+1 to fold the first python indent level (class definitions and functions), alt+2 to fold the second level (class methods), and alt+0 to unfold everything. It makes sure it only folds one level and doesn't fold any of the nested sub levels. You can still use za to toggle folding for the current block. Note that in ^[0, the ^[ is alt for my terminal. Don't have a lot of experience in vim script so feel free to make suggestions on the function :)

" Python folding
nnoremap ^[0 zR<CR>
nnoremap ^[1 :call Fold(0)<CR>
nnoremap ^[2 :call Fold(1)<CR>
function Fold(level)
    :let b:max = a:level + 1
    :set foldmethod=indent
    :execute 'set foldnestmax='.b:max
    :execute 'set foldlevel='.a:level
endfunction
user_103009770

Based on the answer by @Genma I glued together the following syntax rules which just need to be added as .vim/after/syntax/python.vim

syn keyword pythonStatement class def
syn match pythonFunction "\h\w*" containedin=pythonFold
syn region  pythonFold  fold transparent
      \ start = "\(^\z(\s*\)\v%(def|class|if|elif|else|for|while|try|except|finally|with)>)@<="
      \ end   = "\v\ze%(\s*\n)+%(\z1\s)@!."

syn region pythonCurlyBrace start="{" end="}" fold transparent
syn region pythonSquareBrace start="\[" end="\]" fold transparent
user_102474600
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