def yes_no(question, valid_ans):
    error = f"Please enter a valid option from the following list: {valid_ans}"
    # checks users enter yes (y) or no (n)
    while True:

            # Get user response and make sure it's lowercase
            user_response = input(question).lower()

            for item in valid_ans:
                # check if the user response is a word in the list
                if item == user_response:
                    return item

                # check if the user response is the same as
                # the first letter of an item in the list
                elif user_response == item[0]:
                    return item

            # print error if user does not enter something that is valid
                print(error)
                print()



def instructions():
         """Prints instructions"""

         print('''
                *** Instructions ****
        
           ''')



# Main routine

# ask the user if they want instructions (check they say yes / no)
yes_no_list = ["yes", "no"]

# ask the user if they want instructions (check they say yes / no)
want_instructions = yes_no("Do you want to see the instructions? ", yes_no_list)
print(f"you choose {want_instructions}")

# Display the instructions if the user wants to see them...
if want_instructions == "yes":
    instructions()


print()
print("Program continues")