Mise automatically infers Python version from Poetry pyproject.toml file

[JasiekChomiak]

I think a great feature for mise would be to be more plug-and-play when it comes to the Python + Poetry combo.

I feel like Poetry is a quite common use case as a package manager for Python, however mise does not seem to "understand" the pyproject.toml file (like it does, for example,.nvmrcfor node).

It'd be great if upon entering a directory with a pyproject.toml but without a mise.toml file, mise would automatically switch to an existing install that matches the project Python version, or issue a warning if it's not installed. This would allow developers to seamlessly work on projects that don't support mise explicitly.

[jdx]

are you talking about using requires-python? if so I don't think that should be used for detecting the version since that should just provide a range of compatible versions

[JasiekChomiak]

Either this or from poetry dependencies.

As for the range — I think any sensible default (latest matching, for example) would work.

I just mention this because I think it allows for a nice "no modification" developer experience on a tool that uses Poetry, but doesn't have a mise.toml or .python-version file: you just clone the repository, run mise install, and mise figures out which Python version you need.

Still, I just realised the same behaviour could be achieved by having a mise.local.toml, adding it to .gitignore, and specifying the Python version there, which doesn't require to modify the repository 😅

So yeah, I guess this is not really necessary — thanks for the quick response though 🙏🏻!