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 (there's only one that's correct); it just works, simply.

Installation

Use one of the following plugin managers:

• dein
• vim-plug
• vundle
• pathogen

Also strongly recommend using FastFold due to Vim's folding being extremely slow by default.

Configuration

No configuration is necessary. However, there are a few configurable options.

Option variables

Set variable to 1 to enable or 0 to disable.

For example to enable docstring preview in fold text you can add the following command to your ~/.config/nvim/init.vim or ~/.vimrc:

let g:SimpylFold_docstring_preview = 1

Variable	Description	Default
g:SimpylFold_docstring_preview	Preview docstring in fold text	0
g:SimpylFold_fold_docstring	Fold docstrings	1
b:SimpylFold_fold_docstring	Fold docstrings (buffer local)	1
g:SimpylFold_fold_import	Fold imports	1
b:SimpylFold_fold_import	Fold imports (buffer local)	1

Commands

There are also a few buffer local commands for fast toggling:

Command	Description
SimpylFoldDocstrings	Enable docstring folding
SimpylFoldDocstrings!	Disable docstring folding
SimpylFoldImports	Enable import folding
SimpylFoldImports!	Disable import folding

Usage

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 submit pull requests on GitHub! Simple is nice, but simple and correct is much better.

Happy hacking!