There is no good place to put configuration that is both project-specific and per-user. An example of this is where to find the virtualenv(s) for a project. Another example is poetry requires pip config in
pyproject.toml, but that means it needs to be shared by all developers of a project.
Add a new TOML file, perhaps
.pythonconfig, that tools will look for that holds this information. This seems nicer than proposals which require having something that might be a file or a virtualenv. It also has the plus side of being quite flexible and allowing for other configuration as well. Because of established conventions for
pyproject.toml, I think this could be relatively easy to implement.
I can see some potential issues that are created by not having a single file where everything goes. It is also true that for the majority of users this would only include virtualenv info. But these I see as minor downsides for something that would be quite convenient and there is no good solution for currently.