Detect python version from pyproject.toml | Feature Requests

Detect python version from pyproject.toml

Matt Sanders

When using poetry you can specify the python version in pyproject.toml as a poetry dependency.

When this is set it would be nice to detect / use it automatically instead of needing to set the ENV var.

January 20, 2022

Patrick Johnmeyer

I think this would be good. For that matter, this isn't Poetry-specific. requires-python
 is part of the pyproject.toml specification, valid for any PEP-621 compliant package manager. https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#python-requires
The question then becomes what is the correct behavior. Does Render always select the most recent Python that matches the pyproject.toml file? Or does it "cache" the version from the first successful deployment until the requirement changes? The former is better for automatically pulling security updates; the latter is better for reproducible builds.
Or for that matter, if requires-python is flagged as "dynamic" -- then it has to be extracted from the build tool of choice. Of course Render could choose to not support dynamic.