Extension switches back to Jedi when reloading after setting Pylance as the default language server

Environment data

• VS Code version: 1.49.3
• Extension version (available under the Extensions sidebar): v2020.9.114305
• OS and version: Windows 10 2004
• Python version (& distribution if applicable, e.g. Anaconda): 3.8.6
• Type of virtual environment used (N/A | venv | virtualenv | conda | …): N/A
• Relevant/affected Python packages and their versions:
• Relevant/affected Python-related VS Code extensions and their versions: Pylance (v2020.10.0)
• Value of the python.languageServer setting: Jedi

Expected behaviour

Changed the language server to Pylance, and it should stay Pylance.

Actual behaviour

Pylance extension suggests me to change to it’s language server.

Click ‘Yes, and reload’

settings.json

Python extension changes the language server back to Jedi and asks me to reload

I go check settings.json and to my surprise:

Steps to reproduce:

1. Install Python extension and Pylance extension.

2. Create Python ‘project’ with these settings in .vscode

settings.json:

{
    "python.pythonPath": "C:\\Users\\tiago\\AppData\\Local\\Programs\\Python\\Python38\\python.exe"
}

launch.json

{
    "version": "0.2.0",
    "configurations": [
        {
            "name": "Python: Current File",
            "type": "python",
            "request": "launch",
            "program": "${file}",
            "console": "externalTerminal"
        }
    ]
}

1. Python code:

print('hello')

[jakebailey]

Thanks for confirming. For reference, it’s this way because before the languageServer setting was the only setting, jediEnabled needed to be set explicitly to false to get any LS to work. Now jedi is “just another LS setting”, but for compatibility we had to roll people forward; explicitly setting jedi to true meant that we were forcing it to be the LS.

There’s a TODO to remove this, as at this point I’m not expecting there to be many machines configured this way intentionally anymore.

[jakebailey]

Can you check that file to see if there’s a setting python.jediEnabled, even commented out?