#function goses here...
def yes_no(question):
    """checks that users enter yes / y or no / n to a question"""

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

        if responce == "yes" or responce =="y":
            return "yes"
        elif responce =="no" or responce =="n":
            return "no"
        else:
            print("please enter yes(y) or no(n).\n")


#main goses here...

 #loop for testing...
while True:
    want_instructions = yes_no("Do you want to read the instruction?")
    print(f"You chose {want_instructions}\n")