def string_checker(question, valid_ans):
    error = f"Please enter a valid option from the following list: {valid_ans}"

    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()


# Displays instructions

def instruction():
    print('''

        **** Instructions ****
                  
        To begin, choose the number of rounds (or press <enter> for infinite mode).
        
        Then play against the computer. You need to enter R (rock) or P (paper) or S (scissors).
        
        The rules bla bla blah
          
          
          
          ''')

# Main Program


rps_list = ["rock", "paper", "scissors", "xxx"]

yes_no = ["yes", "no"]


want_instructions = string_checker("Do you want to see the instructions? ", yes_no)

if want_instructions == "yes":
    instruction()

# Choose the number of rounds


# User chooses the number of PSR
user_choice = string_checker("choose:", rps_list)
print("You chose: ", user_choice)