how to check for input python code example

Example 1: python check if string is in input

try:
   val = int(userInput)
except ValueError:
   print("That's not an int!")

Example 2: how to do an if input = python

start_over = 1

question = input("Do you wish to try again? y/n: ")
if question == "y":
    start_over -= 1
else:
    raise SystemExit