def int_check(question, low , high):
    """checks user enter an integer / foat that is more than zero"""



    error = f"opps - please enter an interger between {low} and {high}."


    while True:

        try:
            # changing the responce to an integer and check that it is more than 0
            response = int (input(question))

            if low <= response <= high:
                return response
            else:
                print(error)

        except ValueError:
            print (error)

def not_blank(question):
    """checks that the users reponce is not blank"""

    while True:
        response = input(question)

        if response !="":
            return response

        print("Sorry, this cant be blank. please try again.\n")

def string_check(question, valid_ans_list=('yes', 'no'),
                 num_letter=1):
    """checks the users enter the full word or the first letter of a word
    from a list of responces"""

    while True:
        response = input(question).lower()


        for item in valid_ans_list:


            #checks if the response is the entire word
            if response == item:
                return item

            #checks if the responce is the first letter
            elif response == item [:num_letter]:
                return item

        print(f"please choose an option from {valid_ans_list}")

#main routine gose here

#intialise variables / non-default options for string checker

payment_ans = ('cash', 'credit')

#loop for testing
while True:
    print()

    name= not_blank("name: ")


    age = int_check("Age: ")


    if age <12:
        print(f"{name} is too young")
        continue
    elif age >120:
        print(f"{name} is to old")
        continue
    else:
        pass
    payment_method = string_check("paymentmethod:",payment_ans,2)
    print(f"{name} has bought a ticket({payment_method})")