This is fantastic commenting. Thank you for setting the bar.

This include nested quantifiers and could lead to potentially infinite backtracking

Where is the category Best of Best Practices? Right here.

nice one, one small comment you don't need to use ^ and $ because they are using re.fullmatch in the text anyway.

Why would it be ok? See what it does here: https://regex101.com/

In this case, the requirement is to have a password at least six characters long. This seems like a sensible minimum length. The value itself is entirely arbitrary, though.

Use spoiler flag next time.

beautifull

I think regular expressions are not the appropriate tool for this.

Can somebody help me with finding a solution for the same kata but the criteria is different? The criteria changed from 'at least one time' to 'only one time'

I didn't know you can break it down like that