Command line blackjack game

blackjack.py

from random import shuffle, randint as ri
from itertools import product


PLAYER, OP, BOTH, NEITHER = range(4)
suits = ["clubs", "diamonds", "hearts", "spades"]
values = [
    "ace", "two", "three", "four", "five", 
    "six", "seven", "eight", "nine", "ten",
    "jack", "queen", "king"]


class EmptyDeck(Exception):
    pass


class Card(object):
    def __init__(self, suit, value):
        self.suit = suit
        self.value = value

    def __str__(self):
        return "%s of %s" % (self.value, self.suit)


class DeckState(object):
    def __init__(self):
        self._cards = [
            Card(suit, value) for suit, value in 
            product(suits, values)]
        shuffle(self._cards)
        self._top = 51
    
    @property
    def next(self):
        if self._top < 0:
            raise EmptyDeck()
        self._top -= 1
        return self._cards[self._top + 1]


class PlayerState(object):
    def __init__(self):
        self.cards = []

    @property
    def score(self):
        cvalues = [0]
        for card in self.cards:
            if card.value == "ace":
                lv = len(cvalues)
                for i in xrange(lv):
                    cvalues.append(cvalues[i] + 11)
                    cvalues[i] += 1
            else:
                i = values.index(card.value)
                v = i + 1 if i < 10 else 10
                lv = len(cvalues)
                for i in xrange(lv):
                    cvalues[i] += v

        mv = min(cvalues)
        if mv > 21:
            return mv
        best = cvalues[0]
        for v in cvalues[1:]:
            if v < 22 and v > best:
                best = v
        return best

    def append(self, card):
        self.cards.append(card)


class GameState(object):
    def __init__(self):
        self.state = BOTH
        self.turn = PLAYER

    def step(self, resign=False):
        if self.turn == PLAYER:
            if resign:
                assert self.state in (BOTH, PLAYER)
                if self.state == BOTH:
                    self.state = OP
                else:
                    self.state = NEITHER
        else:
            if resign:
                assert self.state in (BOTH, OP)
                if self.state == BOTH:
                    self.state = PLAYER
                else:
                    self.state = NEITHER
        self.turn = (self.turn + 1) % 2


class OpponentStrategy(object):
    def __init__(self):
        pass

    def action(self, op_score, player_score):
        if player_score > op_score and player_score < 22:
            return True
        if player_score > 21:
            return False
        elif op_score > 21:
            return False
        elif op_score < 11:
            return True
        else:
            return ri(0, 10) < 21 - op_score


class Game(object):
    def __init__(self):
        self.deck_state = DeckState()
        self.player = PlayerState()
        self.opponent = PlayerState()
        self.game_state = GameState()
        self.opponent_strategy = OpponentStrategy()

    def iter(self):
        state = self.game_state.state
        turn = self.game_state.turn
        if state == NEITHER:
            ps = self.player.score
            os = self.opponent.score
            print "Your final score is %s and the opponent's final score is %s\n" % (ps, os)
            if ps < 22 and (ps > os or os > 21):
                print "You won\n"
            else:
                print "You lost\n"
            return False
        elif state == BOTH:
            if turn == PLAYER:
                if self.player.score > 21:
                    self.game_state.step(True)
                else:
                    choice = raw_input("Would you like to draw a card? (Y/n)\n")
                    if choice in ("", "y", "Y"):
                        card = self.deck_state.next
                        print "You drew a %s\n" % card
                        self.player.append(card)
                        self.game_state.step()
                    else:
                        self.game_state.step(True)
            if turn == OP:
                if self.opponent_strategy.action(
                        self.opponent.score, self.player.score):
                    card = self.deck_state.next
                    print "The opponent drew a %s\n" % card
                    self.opponent.append(card)
                    self.game_state.step()
                else:
                    print "Your opponent resigned\n"
                    self.game_state.step(True)
        elif state == PLAYER:
            if turn == OP:
                self.game_state.step()
            else:
                if self.player.score > 21:
                    self.game_state.step(True)
                else:
                    choice = raw_input("Would you like to draw a card? (Y/n)\n")
                    if choice in ("", "y", "Y"):
                        card = self.deck_state.next
                        print "You drew a %s\n" % card
                        self.player.append(card)
                        self.game_state.step()
                    else:
                        self.game_state.step(True)
        else:
            if turn == PLAYER:
                self.game_state.step()
            else:
                if self.opponent_strategy.action(
                        self.opponent.score, self.player.score):
                    card = self.deck_state.next
                    print "The opponent drew a %s\n" % card
                    self.opponent.append(card)
                    self.game_state.step()
                else:
                    print "Your opponent resigned\n"
                    self.game_state.step(True)

        return True



if __name__ == "__main__":
    game = Game()
    while game.iter():
        pass
    exit()