Python Language Server Protocol with virtual environment

Question

Can anyone help me get things like "Go to definition" working with Neovim and Python virtual environments?

My setup currently uses a specific virtual environment for Neovim (as recommended by :checkhealth) which is working fine.

I've installed python-language-server and pyls-mypy into that virtual environment.

In my .vimrc I've got w0rp/ale installed with the following configuration:

let g:ale_linters = {
      \ 'python': ['flake8', 'pyls']
      \}
let g:ale_virtualenv_dir_names = ['.venv']

I'm now in a directory with a virtual environment in ./.venv (which isn't activated) and can't get any LSP stuff like :ALEGoToDefinition to work.

What am I missing?

Answer 1

I finally resolved this by installed python-language-server globally like this:

sudo -H pip install python-language-server

I don't know how popular a solution this will be, but it works for me, so I'm happy.

Since the ale documentation for ALEGoToDefinition says

Jump to the definition of a symbol under the cursor using the enabled LSP
linters for the buffer. ALE will jump to a definition if an LSP server
provides a location to jump to. Otherwise, ALE will do nothing.

the language server is probably necessary.