Python二十一点模拟器循环逻辑异常：手牌判断与遍历问题求助

问题背景 #

我是Python新手，正在运行从网上找到的二十一点模拟器，但部分代码逻辑未达预期，尝试多种写法仍未解决。

相关代码 #

# deal player to 12 or higher
while sum(player_cards) <= 12:
    exit = False
    player_cards.append(deck.pop(0))
    # check for limit 
    if sum(player_cards) > 21:
        print("--players_cards >21")
        exit = True
        # check for an ace and convert to 1 if found
        for i, card in enumerate(player_cards):
            print("--card " + str(card))
            if card == 11:
                player_cards[i] = 1
                exit = False
            else:
                return -1   
    if exit:
        break   


# deal dealer on soft 17
while sum(dealer_cards) <= 16:
    exit = False
    dealer_cards.append(deck.pop(0))
    # check for limit 
    if sum(dealer_cards) > 21:
        exit = True
        # check for an ace and convert to 1 if found
        for i, card in enumerate(dealer_cards):
            if card == 11:
                dealer_cards[i] = 1
                exit = False
    if exit:
        break

p_sum = sum(player_cards)
d_sum = sum(dealer_cards)

print("player " + str(player_cards) )
print("dealer " + str(dealer_cards) )

异常输出 #

player [10, 10]
dealer [5, 6, 10]
--players_cards >21
--card 3
player [10, 10]
dealer [10, 9]
--players_cards >21
--card 3
player [7, 10]
dealer [5, 10, 5]

存在的问题 #

• 仅当sum(player_cards) >21时才应打印"--players_cards >21"，但实际在手牌和为20[10,10]、17[7,10]时触发该打印；
• for循环应遍历打印玩家手牌的所有数值，却输出了3。尝试改用range(len())写法后结果类似。

问题分析与修复 #

核心问题根源 #

玩家手牌处理逻辑中的else: return -1是错误的：只要遍历到非11的牌就直接终止函数，导致后续流程被打断，手牌状态混乱，同时循环只执行一次就退出。

修复后的玩家发牌逻辑 #

# deal player to 12 or higher
while sum(player_cards) <= 12:
    exit = False
    player_cards.append(deck.pop(0))
    current_sum = sum(player_cards)
    if current_sum > 21:
        print("--players_cards >21")
        exit = True
        # 遍历手牌，将A(11)转换为1
        for i, card in enumerate(player_cards):
            print("--card " + str(card))
            if card == 11:
                player_cards[i] = 1
                exit = False
                # 转换后已无需继续遍历，跳出循环
                break
    if exit:
        break

修复后的庄家发牌逻辑（可选优化） #

# deal dealer on soft 17
while sum(dealer_cards) <= 16:
    exit = False
    dealer_cards.append(deck.pop(0))
    current_sum = sum(dealer_cards)
    if current_sum > 21:
        exit = True
        # 遍历手牌，将A(11)转换为1
        for i, card in enumerate(dealer_cards):
            if card == 11:
                dealer_cards[i] = 1
                exit = False
                break
    if exit:
        break

修复说明 #

1. 删除了错误的else: return -1，避免函数提前退出，保证循环能正常遍历所有手牌；
2. 转换A后添加break，避免不必要的遍历，提升效率；
3. 增加current_sum变量缓存手牌和，避免重复调用sum()函数，优化性能；
4. 修复后，只有当玩家手牌和真正超过21时才会打印"--players_cards >21"，且for循环会遍历打印所有手牌。

内容的提问来源于stack exchange，提问作者Lalo Fuentes