A bowling simulation

bowling.py

import random

def take_turn(player, total, scores, frame):
	roll = []
	first_ball = first_roll()
	second_ball = 0

	# If it's a strike, add 0 to score this turn
	if is_strike(first_ball):
		roll.append('X')
		# second_ball = 0
		print 'STRIKE'
	else:
		roll.append(first_ball)
		score = first_ball
		second_ball = random.randint(0, 10 - first_ball)
		# If it's a spare, add the score from the first ball
		if is_spare(first_ball, second_ball):
			print 'SPARE'
			roll.append('/')
		else:
			# If it's a normal roll, add the score from the second ball
			roll.append(second_ball)
	# Score for this round
	score = first_ball + second_ball

	# If last round was a spare or strike, add points from this round plus the points that were not added from the last round
	if frame > 1:
		if was_strike(player[frame - 2]):
			total += first_ball + second_ball
			scores[frame - 2] = scores[frame - 2] + first_ball + second_ball
		elif was_spare(player[frame - 2]):
			total += first_ball
			scores[frame - 2] = scores[frame - 2] + first_ball

	# Different scoring rules for the last frame
	if frame == NUM_FRAMES:
		if was_strike(roll):
			print 'STRIKE'
			second_attempt = first_roll()
			if is_strike(second_attempt):
				third_attempt = first_roll()
			else:
				third_attempt = random.randint(0, 10 - second_attempt)
			score += second_attempt + third_attempt
			roll.append(second_attempt)
			roll.append(third_attempt)
		elif was_spare(roll):
			print 'SPARE'
			third_attempt = first_roll()
			score += third_attempt
			roll.append(third_attempt)

	total += score
	scores.append(score)
	player.append(roll)
	print 'Pins: ' + str(player)
	print 'Points: ' + str(scores)
	print 'Score for round: ' + str(score)
	print 'Total score: ' + str(total)
	return player, scores, total


def was_strike(roll):
	return roll[0] == 'X'

def was_spare(roll):
	return roll[1] == '/'

def is_strike(roll_1):
	return roll_1 == 10

def is_spare(roll_1, roll_2):
	return (roll_1 + roll_2) == 10

def first_roll():
	return random.randint(0, 10)


while True:
	user_input = raw_input("Would you like to play a game?\n")

	if str(user_input) == 'Yes':
		player_1 = []
		player_2 = []
		player_1_total = 0
		player_2_total = 0
		player_1_scores = []
		player_2_scores = []

		NUM_FRAMES = 10

		for frame in xrange(1, NUM_FRAMES + 1):
			print 'FRAME ' + str(frame) + '\n'
			print 'Player 1: '
			player_1, player_1_scores, player_1_total = take_turn(player_1, player_1_total, player_1_scores, frame)
			print '\nPlayer 2: '
			player_2, player_2_scores, player_2_total = take_turn(player_2, player_2_total, player_2_scores, frame)
			print '\n'


	elif str(user_input) == 'No':
		exit()
	else:
		print "Type Yes or No\n"