No fold found with python code, mac and debian

Question

I'm trying to get vim to do code folding with my python code and I could really use your help with the last bit here.

I have this in my ~/.vimrc:

set number
"set tabstop=2
"set expandtab
"set sw=2
set nowrap
syntax on
set linebreak
set textwidth=80
set background=dark

" Enable folding
set foldmethod=indent
set foldlevel=99
filetype plugin indent on

" Enable folding with the spacebar
nnoremap <space> za

I've been testing with the following file

from filelock import FileLock
import yaml

def main() -> int:
    """
    main control loop
    """
    #Read config file
    read_config()
    #Lock

I've tried this file with double spaces, four spaces, single tabs, so far nothing has worked. Everything results in "E490 fold not found".

I've tried running set foldmethod=indent after loading the file, I've confirmed that :set syntax returns syntax=python, I've tried a ruby file and code folding works there so it appears to be something about the python I've crafted that it doesn't like. I've tried without the python type hinting (-> int), no change.

I tried installing vim from brew, confirmed I'm using vim from the new path, no change.

I've tried replicating this on a Debian Buster vm so I don't think it's mac specific.

I even tried putting an 'end' which isn't syntactically correct at the end of the function definition just as an experiment, that didn't work either.

This is the output of vim --version

macOS version - x86_64
Included patches: 1-2900
Compiled by Homebrew
Huge version without GUI.  Features included (+) or not (-):
+acl               -farsi             +mouse_sgr         +tag_binary
+arabic            +file_in_path      -mouse_sysmouse    -tag_old_static
+autocmd           +find_in_path      +mouse_urxvt       -tag_any_white
+autochdir         +float             +mouse_xterm       -tcl
-autoservername    +folding           +multi_byte        +termguicolors
-balloon_eval      -footer            +multi_lang        +terminal
+balloon_eval_term +fork()            -mzscheme          +terminfo
-browse            +gettext           +netbeans_intg     +termresponse
++builtin_terms    -hangul_input      +num64             +textobjects
+byte_offset       +iconv             +packages          +textprop
+channel           +insert_expand     +path_extra        +timers
+cindent           +ipv6              +perl              +title
-clientserver      +job               +persistent_undo   -toolbar
+clipboard         +jumplist          +popupwin          +user_commands
+cmdline_compl     +keymap            +postscript        +vartabs
+cmdline_hist      +lambda            +printer           +vertsplit
+cmdline_info      +langmap           +profile           +virtualedit
+comments          +libcall           -python            +visual
+conceal           +linebreak         +python3           +visualextra
+cryptv            +lispindent        +quickfix          +viminfo
+cscope            +listcmds          +reltime           +vreplace
+cursorbind        +localmap          +rightleft         +wildignore
+cursorshape       +lua               +ruby              +wildmenu
+dialog_con        +menu              +scrollbind        +windows
+diff              +mksession         +signs             +writebackup
+digraphs          +modify_fname      +smartindent       -X11
-dnd               +mouse             -sound             -xfontset
-ebcdic            -mouseshape        +spell             -xim
+emacs_tags        +mouse_dec         +startuptime       -xpm
+eval              -mouse_gpm         +statusline        -xsmp
+ex_extra          -mouse_jsbterm     -sun_workshop      -xterm_clipboard
+extra_search      +mouse_netterm     +syntax            -xterm_save
   system vimrc file: "$VIM/vimrc"
     user vimrc file: "$HOME/.vimrc"
 2nd user vimrc file: "~/.vim/vimrc"
      user exrc file: "$HOME/.exrc"
       defaults file: "$VIMRUNTIME/defaults.vim"
  fall-back for $VIM: "/usr/local/share/vim"
Compilation: clang -c -I. -Iproto -DHAVE_CONFIG_H -DMACOS_X -DMACOS_X_DARWIN -g -O2 -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=1
Linking: clang -L. -fstack-protector-strong -L/usr/local/lib -L/usr/local/opt/libyaml/lib -L/usr/local/opt/[email protected]/lib -L/usr/local/opt/readline/lib -L/usr/local/lib -o vim -lm -lncurses -liconv -lintl -framework AppKit -L/usr/local/opt/lua/lib -llua5.4 -mmacosx-version-min=11.3 -fstack-protector-strong -L/usr/local/lib -L/usr/local/Cellar/perl/5.34.0/lib/perl5/5.34.0/darwin-thread-multi-2level/CORE -lperl -L/usr/local/opt/[email protected]/Frameworks/Python.framework/Versions/3.9/lib/python3.9/config-3.9-darwin -lpython3.9 -framework CoreFoundation -lruby.3.0 -L/usr/local/Cellar/ruby/3.0.1/lib

Any ideas how else to poke at or fix this? It's probably something small and silly so Ill apologize now, I just can't see it at the moment.. Thanks in advance!

References:

• https://vim.fandom.com/wiki/Folding
• https://stackoverflow.com/questions/19441014/macvim-can-not-fold-code-e490-no-fold-found
• https://old.reddit.com/r/vim/comments/49c882/vim_intended_folding_e490_no_fold_found/

Update1: Added filetype plugin indent on to vimrc, recommended in comments.

Answer 1

EDIT You also need to add the following line to your vimrc:

filetype plugin indent on

See :h :filetype-plugin-on and :h :filetype-indent-on this command enable the filetype detection and the loading of the indent scripts which are necessary to have working folding.

---

You can't set foldmethod directly from the vimrc, see :h 'fdm':

'foldmethod' 'fdm'  string (default: "manual")
            local to window

The key words here are local to window: Setting the fold method in your vimrc will not affect the other splits you open.

You need to create a ftplugin :h ftplugin for python and put the setting in it. Create ~/.vim/after/ftplugin/python.vim and put your set foldmethod=indent there.

Answer 2

With the settings you have it should work.

Press zM to close all folds. Note if you press za on def main it would not toggle the fold -- it doesn't exist on that line. Put your cursor on indented line and press za there

PS

Make sure you have matching shiftwidth to your actual indent.