New Python path experiment does in fact change the python.defaultInterpreterPath

[rohrbrecher]

VS Code version

1.62.2

Extension version

v2021.11.1422169775

OS type

Windows

OS version

Windows 10

Python distribution

python.org

Python version

3.6.5

Language server

Default

Expected behaviour

The python extension now uses an internally stored python interpreter path or it will fall back to the default path in the settings. The following order is applied:

1. Python path defined within the extension on folder level
2. Python path defined within the extension on workspace level
3. Python path defined within the folder settings (python.defaultInterpreterPath)
4. Python path defined within the workspace settings (python.defaultInterpreterPath)
5. Python path defined within the user settings (python.defaultInterpreterPath)

The documentation (e.g. here https://github.com/microsoft/vscode-python/wiki/AB-Experiments) clearly states that the python.defaultInterpreterPath setting is only read but never modified by the extension.
If a python interpreter is selected using the command "Python: Select Interpreter" the selection is stored "internally" and the settings.json is not affected.

Actual behaviour

When working with a single .py file only, no folder or workspace loaded, using the "Python: Select Interpreter" or "Python: Clear Workspace Interpreter Setting" command will add/change/remove the python.defaultInterpreterPath within the users settings.json.

Steps to reproduce

• load any python file in an empty VSCode instance
• VSC will probably use the "recommended" python interpreter
• open the user settings.json and define a "python.defaultInterpreterPath" (best to use a different python than the recommended one)
• use the command "Python: Select Interpreter" to pick a different interpreter
• observe that the defaultInterpreterPath has been changed
• use the command "Python: Clear Workspace Interpreter Setting"
• observe that the defaultInterpreterPath is completely removed from the settings

Logs

No response

Code of Conduct

• I agree to follow this project's Code of Conduct

[karthiknadig]

@luabud this seems like it needs some clarification in the docs. We only set python.defaultInterpreterPath in one special case, that is when users open a file without opening a workspace, and run select interpreter. In all other cases, we just read from the setting.

I think, in cases like that, we should save that data in our internal storage and not update python.defaultInterpreterPath. python.defaultInterpreterPath should only be read only.

/cc @karrtikr

[karrtikr]

I think, in cases like that, we should save that data in our internal storage and not update python.defaultInterpreterPath. python.defaultInterpreterPath should only be read only.

If we do that then python.defaultInterpreterPath at User level won't be of any use 🤷‍♂️ I'm in favor of clarifying the docs here.

[luabud]

oh I didn't realize we wrote to this setting in that scenario, I thought it was completely read only.

I don't particularly agree that it wouldn't be of any use if we didn't modify the setting, because it's still useful to have e.g. the same global environment for every new workspace. That said, if we wish to keep this behaviour, we do indeed need to update the docs.

[karrtikr]

I guess I misunderstood how internal storage is supposed to store, is it supposed to store settings just for the particular file which is opened?

[rohrbrecher]

I'm with @luabud: I listed the order in which the different settings are being used in my initial finding and I think it's good this way. Many users never want to switch interpreters and for them it's best if they just define it using defaultInterpreterPath in their user or workspace settings.

[karrtikr]

We have decided to clarify it in the docs: https://github.com/microsoft/vscode-python/wiki/AB-Experiments, the behavior is as you described, closing this.