AB Experiments
The Python extension and VS Code often A/B test new features. You can check the experiments you're part of by enabling telemetry log tracing and checking the list under the "VSCode.ABExp.Features" key.
If you wish to opt-out of A/B testing in the Python extension, you can open the user settings.json file (View > Command Palette… and run Preferences: Open User Settings (JSON)) and set the python.experiments.enabled setting to false.
Alternatively, you can opt-in and opt-out of specific experiments through the python.experiments.optInto and python.experiments.optOutFrom settings. You can rely on the auto completions in VS Code to see which experiments you can opt-into and out from.
You can also disable telemetry to opt out of A/B testing from VS Code and all other Microsoft extensions. You can find more information about how VS Code handles telemetry at our documentation and at the Microsoft Privacy Statement.
See https://github.com/microsoft/vscode-python/blob/main/src/client/common/experiments/groups.ts for any experiments going on currently.
Some experiments may override default settings values. To find out whether you have impacted settings, you can open the settings UI page (File > Preferences > Settings) and search for @modified. This will list all your settings that have been modified by you or by an experiment. In the latter case, you will see a marker indicating that the default value of that setting has been changed by an experiment.
Q: Can I opt out of the experiment?
A: You can opt out of any experiment by opening the user settings.json file and set the "python.experiments.optOutFrom" setting to ["All"], or to specific experiments you wish to opt out from. You can also disable telemetry to opt out of A/B testing from VS Code and all other Microsoft extensions.
Q: How do I know if I’m part of the experiment?
A: To see if you are part of a Python extension experiment, you can check the first lines in the Python extension output channel. You can also check all the experiments you're part of in VS Code by enabling telemetry log tracing and searching for the "VSCode.ABExp.Features" key.
Q: How do I add myself to an experiment?
A: You can opt in an experiment by adding python.experiments.optInto to your User settings. You can rely on the auto completions in VS Code to see which experiments are available.
Q: How do I report a problem I’m having with this experiment?
A: If you’re having a problem with the experiment or wish to provide feedback, please create a new issue at https://github.com/Microsoft/vscode-python/issues.