Rock, Paper, Scissors

import random
ROCK=0
PAPER=1
SCISSORS=2

TIE=0
WIN=1
LOSE=-1

def createRpsTable():
    rpsTable=list()
    rpsTable.append([None, None, None])
    rpsTable.append([None, None, None])
    rpsTable.append([None, None, None])
    rpsTable[ROCK][ROCK]=TIE
    rpsTable[ROCK][PAPER]=LOSE
    rpsTable[ROCK][SCISSORS]=WIN
    rpsTable[PAPER][ROCK]=WIN
    rpsTable[PAPER][PAPER]=TIE
    rpsTable[PAPER][SCISSORS]=LOSE
    rpsTable[SCISSORS][ROCK]=LOSE
    rpsTable[SCISSORS][PAPER]=WIN
    rpsTable[SCISSORS][SCISSORS]=TIE
    return rpsTable

def main():
    rpsTable=createRpsTable()
    while True:
        wantsToContinue=runGame(rpsTable)
        if not wantsToContinue:
            break

def runGame(rpsTable)
    playerChoice=raw_input("Rock, Paper, or Scissors? ").lower()
    while True:
        if playerChoice="rock":
            playerChoice=ROCK
        elif playerChoice="paper":
            playerChoice=PAPER
        elif playerChoice="scissors":
            playerChoice=SCISSORS
        else:
            print "Invalid choice."
            continue
        break

    computerChoice=random.randint(0,2)
    if computerChoice=ROCK:
        print "The computer chose rock."
    elif computerChoice=PAPER:
        print "The computer chose paper."
    else:
        print "The computer chose scissors."

    result = rpsTable[playerChoice][computerChoice]
    if result=WIN:
        print "Congratulations, you win!"
    elif result=LOSE:
        print "Looks like the computer beat you this round."
    else:
        print "It was a tie this time."

    playAgain=raw_input("Do you want to play again? (yes, no)").lower()
    if playAgain in ('y', 'yes'):
        return True
    return False

if __name__=='__main__':
    main()