title: How to check if input is a natural number in Python?
body: <p>Right now I'm trying to make a simple tic-tac-toe game, and while user chooses the sector of the board for their next move I need to check if the input is a <em>single-digit natural number</em>. I don't think just making a <code>['1','2','3'...'9']</code> list and calling an in statement for it is the most optimal thing. Could you suggest anything?</p>