For developers and those who need most recent or different but non-default Python versions, Ubuntu now has an “official” backport PPA for Ubuntu 22.04, Ubuntu 24.04, and Ubuntu 26.04 LTS.
Ubuntu has Python pre-installed, but it won’t update the major version number. It has Python 3.10 for Ubuntu 20.04, Python 3.12 for Ubuntu 24.04, and Ubuntu 26.04 so far defaults to Python 3.13.