def int_check(question): """Checks users enter an integer that is more than zero (or the optional exit code)""" error = "Oops - please enter an integer more than zero." while True: try: # return the response if it's an integer response = int(input(question)) return response except ValueError: print(error) def not_blank(question): """Checks that a user response is not blank""" while True: response = input(question) if response != "": return response print("Sorry this can't be blank. Please try again. \n") def string_check(question, valid_answers=['yes', 'no'], num_letters=1): """Checks that users enter the full word or the 'n' letter/s of a word from a list of valid responses""" while True: response = input(question).lower() for item in valid_answers: # check if the response is the entire word if response == item: return item # check if it's the 'n' letters elif response == item[:num_letters]: return item print(f"Please choose an option from {valid_answers}") # Main routine # initialising variables / non-default options for string checker payment_ans = ('cash', 'credit') while True: print() # ask user for their name (and check it's not blank) name = not_blank("Name: ") # ask user for their age and check it's between 12 and 120 age = int_check("Age: ") # output error message / success message if age < 12: print(f"{name} is too young") continue elif age > 120: print(f"{name} is too old") continue else: pass # ask user for payment method cash or credit pay_method = string_check("Payment method: ", payment_ans, 2) print(f"{name} bought a ticket ({pay_method})")