# Check that users have entered a valid answer
# option based on list

def string_checker(question, valid_ans=('yes', 'no')):

    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 entre something that is valid
        print(error)
        print()



# Displays instructions
def instructions():
    """Print instructions"""

    print("""
*** Instructions ****

To begin, choose the number of rounds (or press <enter> for infinite mode)

Then play against computer. You need to choose R (rock), P (paper) or S (scissors)

The rules are as follows: 
o   Paper beats rock
o   Rock beats scissors
o   Scissors beats paper

Press <xxx> to end game at anytime

Good Luck!
    """)


# Main routine
print()
print("💎📄✂ Rock / Paper / Scissors Game ✂📄💎")
print()

# ask user if they want to see the instructions and display
# them if requested
want_instructions = string_checker("Do you want to see the instructions? ")

# checks users entre yes (y) or no (n)
if want_instructions == "yes":
    instructions()

print()
print("Program continues")