I have done it before haha

It's actually a pretty good solution considering the geniosity of it.

Is there a 'worst' practice button?

Is it normal to switch on a true?

Cheater

Yes, you can put anything in a list. What is it that you really want to do? What problem are you trying to solve with this?

In Python can you have a list where some items in it are lists are some items are numbers?

If so then my solution won't work.

This will only get the nesting count of the first set of nests, which only really works if your list does not have unbalanced nesting. Possibly a more useful way would be to record all of the nests and only return a number if all of the values are the same.