Go to definition with LSP

Question

I'm trying to use Jedi to do "jump-to-definition". For example, if my cursor is on MLPClassifier, I want to be able jump to the place where that class is defined in Python code from the imported library sklearn.

The documentation and this post suggest that I should be able to do this by pressing "\d" while my cursor is on the function/class. However, this does not work.

I think Jedi is installed correctly because autocomplete suggestions seem to work (for example, typing np.arg pops up a menu with argmax, argmin, etc.). Curiously however, running :help jedi-vim gives me "E149: Sorry, no help for jedi-vim".

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FYI about my setup:

• I am not using a virtual environment. It's a system-level Python 3.9

• I'm using Asynchronous Lint Engine (ALE) as my Language Server Protocol (LSP) client.

cd ~/.vim/pack/vendor/start/
git clone [email protected]:dense-analysis/ale.git

• I'm using python-lsp-server as my LSP server. This uses Jedi internally for autocomplete and jump-to-definition.

pip install python-lsp-server

• Here are my plugin-related variables in my .vimrc.

let g:ale_linters = {'python': ['pylsp']}
let g:ale_completion_enabled = 1
let g:ale_linters_explicit = 1
let g:ale_sign_column_always = 1
packloadall
silent! helptags ALL-

Answer 1

I could reproduce your problem.

It seems to me that Jedi is able to find the definition of your project methods and functions but is not very good at finding the library definition.

I have a different experience with coc-nvim that I encourage your to try.

For Python you'll have to:

1. Install coc and
2. Install coc-pyright using the Vim command:

:CocInstall coc-pyright

With coc-pyright the gd command bring me successfully to the definition of sklearn.neural_network.MLPClassifier().

Answer 2

Given the setup with ALE/pylsp/Jedi, we can go to definition by moving a cursor over a function name and typing :ALEGoToDefinition -vsplit.

Notice that this is an ALE command as opposed to a Jedi command. I speculate that this is expected behavior because ALE is the LSP client, and therefore it probably must mediate any on-screen changes. If Jedi were installed on its own, I would expect that \d to work as stated in the Jedi docs.

Figuring out how the various plugins interact with each other via overlapping functionality can be very thorny.