SimpylFold

Because of its reliance on significant whitespace rather than explicit block delimiters, properly folding Python code can be tricky. The Python syntax definition that comes bundled with Vim doesn't contain any fold directives at all, and the simplest workaround is to :set foldmethod=indent, which usually ends up folding a lot more than you really want it to.

There's no shortage of Vim plugins for improved Python folding, but most seem to suffer from cobbled-together algorithms with bizarre, intractable bugs in the corner cases. SimpylFold aims to be exactly what its name suggests: simple, correct folding for Python. It's nothing more than it needs to be: it properly folds class and function/method definitions, and leaves your loops and conditional blocks untouched. There's no BS involved: no screwing around with unrelated options (which several of the other plugins do), no choice of algorithms to scratch your head over (because there's only one that's correct); it just works, simply.

Installation

Pathogen

If you're using Pathogen and Git to manage your Vim plugins (highly recommended), you can just

cd ~/.vim
git submodule add https://github.com/tmhedberg/SimpylFold.git bundle/SimpylFold
git submodule init

and you're good to go.

Vundle

If you use Vundle then put in your .vimrc:

Plugin 'tmhedberg/SimpylFold'

and then launch vim and run :PluginInstall.

NeoBundle

If you use NeoBundle then put in your .vimrc:

NeoBundle 'tmhedberg/SimpylFold'

and then launch vim and run :NeoBundleInstall.

Manually

If you insist on doing this manually, then just clone this repo somewhere or just grab the tarball, and drop the plugin file into your ~/.vim/ftplugin/python.

Configuration

No configuration is necessary. However, if you want to enable previewing of your folded classes' and functions' docstrings in the fold text, add the following to your .vimrc:

let g:SimpylFold_docstring_preview = 1

And if you don't want to see your docstrings folded, add this:

let g:SimpylFold_fold_docstring = 0

And if you don't want to see your imports folded, add this:

let g:SimpylFold_fold_import = 0

In order for SimpylFold to be properly loaded in certain cases, you'll have to add lines like the following to your .vimrc (see issue #27):

autocmd BufWinEnter *.py setlocal foldexpr=SimpylFold(v:lnum) foldmethod=expr
autocmd BufWinLeave *.py setlocal foldexpr< foldmethod<

If you have the above options set to different values anywhere (e.g. setting foldmethod=syntax in .vimrc, SimpylFold won't work properly.

Usage

SimpylFold doesn't define any custom commands. Just use Vim's built-in folding commands to expand and collapse folds. The most basic commands are zc to close a fold and zo to open one. See :help fold-commands for full documentation.

Bugs

If you find any bugs, please report them and/or submit pull requests on Github! Simple is nice, but simple and correct is much better.

Happy hacking!

j3r3miah/SimpylFold