The issue is with how CMD and ENTRYPOINT work together. Your CMD isn't working because it is trying to run bash with no arguments, rather than setting up python as the base command.​​​​​​​​​​​​​​​​ Here's how I’ll fix this:

FROM python:3.11-slim

ENTRYPOINT ["python"]

The difference is:

• CMD gives a default command that can be completely replaced
• ENTRYPOINT sets the base command that docker run arguments get added to

So with ENTRYPOINT ["python"]:

• docker run image --version becomes python --version
• docker run image script.py becomes python script.py

Also, this blogpost breaks these concepts down pretty well. https://www.docker.com/blog/docker-best-practices-choosing-between-run-cmd-and-entrypoint/