# Functions go here
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 range 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 goes here
payment_ans = ('cash', 'credit')


want_instructions = string_check("Do you want to see the instructions? ")
if want_instructions == "yes":
    print("Instructions would display")
print()

pay_method = string_check("Choose a payment method cash(ca) or credit(cr): ",payment_ans, 2 < 6)
if pay_method == "cash":
    print(f"You chose to pay by cash")
else:
    print(f"You chose {pay_method}")

print()
print("The program has ended")