How to install or upgrade Black in Vim 8?

This method of installing Black uses the built-in plugin management in Vim 8+.

mkdir -p ~/.vim/pack/python/start/black/plugin
mkdir -p ~/.vim/pack/python/start/black/autoload
curl https://raw.githubusercontent.com/psf/black/stable/plugin/black.vim -o ~/.vim/pack/python/start/black/plugin/black.vim
curl https://raw.githubusercontent.com/psf/black/stable/autoload/black.vim -o ~/.vim/pack/python/start/black/autoload/black.vim

Open Vim and format your code with:

:Black

To format when saving, add the following to ~/.vimrc:

autocmd BufWritePre *.py execute ':Black'

Upgrading

To upgrade, remove the old Black installation:

rm -r ~/.vim/black

Pull in the new versions of the plugins

curl https://raw.githubusercontent.com/psf/black/stable/plugin/black.vim -o ~/.vim/pack/python/start/black/plugin/black.vim
curl https://raw.githubusercontent.com/psf/black/stable/autoload/black.vim -o ~/.vim/pack/python/start/black/autoload/black.vim

Open Vim and run :Black again.