# Functions go here

# Check that users have entered a valid option based on a 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 enter something valid
          print(error)
          print()


def instructions():
     # Prints instructions

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

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

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

The rules are as follows:
* Paper covers rock
* Rock crushes scissors
* Scissors cuts paper

Press <xxx> to end the game at any time.

Good Luck! """)
# Main Routine

# testing loop...

want_instructions = string_checker("Do you want to see the instructions? ").lower()

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

print()
print("Program continues")