In pyvenv.cfg, there's a version field that records ".".join(sys.version_info[:3]). The interesting thing about this is it isn't loose enough to reflect the version accurately if the Python interpreter is updated in-place (e.g. going from Python 3.11.1 to 3.11.2). But it's also not accurate enough to reflect the exact Python version (e.g. Python 3.12.0a6 is recorded as 3.12.0).

Because of this I'm not sure what the number is meant to represent. If it's meant to record what the version was when the virtual environment was created then we should either change the field to record the release level or add another field that records that. But if it's just meant to record what the version might be, then it's a bit too specific.