Simple command-line Rock, Paper, Scissors game.

rps.py

#!/usr/bin/env python

"""
Simple command-line based Rock Paper Scissors game in Python.
"""
import random
vals = 'R P S'.split(' ')
msg_win = "You win this round."
msg_lose = "You lose this round."
msg_tie = "Tie! You both picked "
help = "Enter R for rock, P for paper, S for scissors, H for help, or Q to quit."

def fight(userval):
    """
    Function to run a fight.
    """
    compsel = random.randint(0, len(vals)-1)
    compval = vals[compsel]
    print "Computer picked %s." % (compval)
    if compval == userval: 
        return 0, '%s%s.' % (msg_tie, compval)
    elif (userval == 'R' and compval == 'P') or (userval == 'P' and compval == 'S') or (userval == 'S' and compval == 'R'):
        return -1, '%s %s beats %s.' % (msg_lose, compval, userval)
    else:
        return 1, '%s %s beats %s.' % (msg_win, userval, compval)
    
def loop():
    """
    Function to run a game loop.
    """
    score = [0, 0]
    print ""
    print ""
    print "Rock Paper Scissors"
    print "-------------------"
    print ""
    print help
    print ""
    print "Let's fight!"
    while 1:
        userval = raw_input("-->")
        userval = userval.upper()
        if userval == 'Q':
            print "Final Score: %s to %s" % (score[0], score[1])
            if score[0] > score[1]:
                print "You win!"
            elif score[0] < score[1]:
                print "You Lose!"
            else:
                print "You tied."
            break
        elif userval == 'H':
            print help
            print ""
        elif userval in vals:
            result, message = fight(userval)
            print message
            if result == 1: score[0] += 1
            elif result == -1: score[1] += 1
            print "Score: %s to %s." % (score[0], score[1])
            print ""
        else:
            print "%s is not a valid command." % (userval)
            print ""

if __name__ == '__main__':
    loop()