Command 'Python: Restart Language Server' resulted in an error (command 'python.analysis.restartLanguageServer' not found)

Hello, there! I just saw the news in the release notes of 2020.8.101144: ‘Add “Restart Language Server” command.’ and was excited! This way I just got the notion about a completely new background Language Server, as a dedicated replacement for Jedi? 👍

I see that note about the new language server and the possible relation but this seems like a feature above the language server itself! So yes: If I set python.languageServer to Pylance there are other issues but I can restart with this command 👍

Now if it’s vscode-python that starts Jedi as a language server. That command should be able to restart it?

Environment data

• VS Code version: 1.48.0
• Extension version: 2020.8.101144
• OS and version: Windows 10 Pro 2004
• Python version: 2.7.18 / 3.8.4
• Value of the python.languageServer setting: Jedi

[NOTE: If you suspect that your issue is related to the Microsoft Python Language Server (python.languageServer: 'Microsoft'), please download our new language server Pylance from the VS Code marketplace to see if that fixes your issue]

Expected behaviour

Language Server restarts

Actual behaviour

Error message:

Command 'Python: Restart Language Server' resulted in an error (command 'python.analysis.restartLanguageServer' not found)

Steps to reproduce:

1. Set language server to Jedi
2. in command palette call Python: Restart Language Server

[karthiknadig]

@JP01 Try this and see if it helps. Some times it is just a bad install. Looks like you might have a bad update. Do the following to remove stale versions of the extension:

1. Uninstall Python extension (if you have pylance uninstall it first).
2. Close all instances of VS Code.
3. Go to, %USERPROFILE%/.vscode/extensions (on windows) or ~/.vscode/extensions on Linux/Mac.
4. Delete any folder with the name starting with ms-python.python*
5. Start VS Code, and install Python extension (also pylance if you uninstalled it in step 1).

[sloria]

Ah, after I re-created my virtualenv (I’m using pyenv+pyenv-virtualenv), restarted VS Code, then re-selected the interpreter using Python: Select Interpreter, the issue is resolved for me.