The problem is that 3.12 is not

[lucid steeple]

Just for me to get more professional: where do I read that 3.12 is not supported for bookworm?

[shut folio]

If you install Bookworm and type 'Python' with a '-V' argument you'll see:

 ▶ python -V
Python 3.11.2

So that's the version delivered with Bookworm. Even if you do a full sudo apt upgrade it will still remain as 3.11.2.

I'm sure you realise that Python is part of the Linux operating system, and the version that comes with Bookworm is 3.11. So upgrading to 3.12 would break compatibility in every case where Python 3.12 differs from 3.11. In all cases where 3.11 and 3.12 are the same you'd have no problem, but in cases where they differ the results would be indeterminate. So at best that'd be considered "risky."

I'm not sure where you can read this more "professionally" but as with all software, using the wrong version may result in an indeterminate situation, i.e., even if it seems to work you can never be sure the results are what you expect.

[lucid steeple]

Thanks so much. One question: actually I used miniconda on Raspberry pi 5 and there I successfully installed python 3.12 in PI5. But this didnt work on Pi Zero 2W. It would hang when trying to create an environment. Is there no way I can get 3.12 in a environment under PI Zero 2W?

[shut folio]

Yes, you can by following my recommendation of using a virtual environment. That way 3.11 remains the version for the OS, and you use 3.12 in your virtual environment. Yes, you'd need to learn how to do that, but that's the only safe way to do it, and it's how "professionally" you'd do it. You'd search on "how to use a virtual environment in python to install a different version of python" to find out how. The official documentation is at: https://docs.python.org/3/library/venv.html

There's also: https://smuhabdullah.medium.com/how-to-use-different-python-versions-with-virtualenv-907b2998b16e
(which I just found)