Previously if a new app did not specify a Python version via a runtime.txt file or the appropriate Pipfile config option, then the buildpack would default to the latest Python 3.11 release.
Now the buildpack will use the latest Python 3.12 release.
This does not affect:
apps that specify an explicit Python version
existing apps that have already had a build using the previous default version (since that version is remembered from one build to the next, via the "sticky versions" feature).
However most apps should be compatible, since Python 3.12 was released a couple of months ago (2023-10-02), does not contain significant breaking changes over Python 3.11, and has been happily used by the python-getting-started project since 2023-10-04.
edmorley
commented
10 months ago
Previously if a new app did not specify a Python version via a
runtime.txtfile or the appropriatePipfileconfig option, then the buildpack would default to the latest Python 3.11 release.Now the buildpack will use the latest Python 3.12 release.
This does not affect:
Use-cases involving new apps that aren't compatible with Python 3.12 will now need to specify Python 3.11 explicitly: https://devcenter.heroku.com/articles/python-support#specifying-a-python-version
However most apps should be compatible, since Python 3.12 was released a couple of months ago (2023-10-02), does not contain significant breaking changes over Python 3.11, and has been happily used by the python-getting-started project since 2023-10-04.
See: https://docs.python.org/3.12/whatsnew/3.12.html
GUS-W-14217493.