How to show documentation when entering function parameters?

[quantum-booty]

I am using the jedi-ls with Nvim-lsp.
When using pyls, the documentation shows when I am writing function parameters, whereas jedi-ls only shows the signature help. How can I replicate the behaviour like in pyls?

Pyls:

Jedi-ls:

[pappasam]

Ah, this is something I'd ideally like to support, but I've run into some issues with nvim-lsp and its treatment of undefined values that has made me shy away from implementing this feature at this time.

In short, there's a pygls limitation at present where Python's None is treated as both Javascript undefined and null. nvim-lsp does not handle null and undefined in an elegant way, which will break your language server. To get around this / support Neovim's native language server, I've avoided adding this feature.

See #38

That said, if you were able to verify that Neovim's lsp implementation tolerates this ambiguity between null and undefined (coc currently tolerates it), I'd be happy to implement!

[pappasam]

Also see my pull request with pygls: openlawlibrary/pygls#132. It's been completely ignored, so I'm not sure solutions to this problem are being prioritized at this time.

[pappasam]

And here's the pygls issue: openlawlibrary/pygls#124