声明在hit_or_stay函数中作为全局变量播放，但是在运行程序时提示“名称错误：未定义播放”时会不断出错，该如何解决？
我在hit_or_stand（）中使用了全局玩法来根据玩家的输入来控制游戏流程。当我运行代码时，出现错误“ NameError：未定义名称播放”。我试图将“全局播放”移到hit_or_stay（）之外，但似乎没有任何效果。
import random
suits = ('Hearts', 'Diamonds', 'Spades', 'Clubs')
ranks = ('Two', 'Three', 'Four', 'Five', 'Six', 'Seven', 'Eight', 'Nine', 'Ten', 'Jack', 'Queen', 'King', 'Ace')
values = {'Two':2, 'Three':3, 'Four':4, 'Five':5, 'Six':6, 'Seven':7, 'Eight':8, 'Nine':9, 'Ten':10, 'Jack':10,
'Queen':10, 'King':10, 'Ace':11}
class Deck:
'''
CREATES DECK, SHUFFLES DECK, DEALS CARDS.
'''
#CREATES DECK BY ADDING EACH SUIT TO EACH RANK AND STORING IN LIST SELF.DECK
def __init__(self):
self.deck = []
for s in suits:
for r in ranks:
self.deck.append(r + ' of ' + s)
#SHUFFLE DECK CREATED IN __init__()
def shuffle(self):
random.shuffle(self.deck)
#DEALS CARD FROM SELF.DECK AT GAME START AND IF PLAYER CHOOSES TO HIT
def deal(self):
single_card = self.deck.pop()
return single_card
#PRINTS CARDS IN SELF.DECK (FOR TROUBLESHOOTING)
def __str__(self):
for card in self.deck:
return str(self.deck)
#print('\n')
##create an instance of Deck class and print the deck
#test_deck = Deck()
#print(test_deck)
#print('\n')
##shuffle and print the deck
#test_deck.shuffle()
#print(test_deck)
#print('\n')
class Card:
'''
CREATES CLASS FOR INDIVIDUAL CARDS, PRINTS INIDIVIDUAL CARDS "SUIT OF RANK"
'''
#CREATES CHARACTERISITCS OF class Card; self.suit and self.rank
def __init__(self,suit,rank):
self.suit = suit
self.rank = rank
class Hand:
'''
HOLDS CARD OBJECT FROM self.deck USING Deck.deal() method
CALCULATES THE VALUE OF THE CARDS IN HAND
ADJUST FOR ACES WHEN APPROPRIATE
'''
#CREATE CHARATERISTICS FOR CARDS IN HAND; self.card = cards in hand, self.value = value of cards in hand, self.aces = counts aces in hand
def __init__(self):
self.cards = []
self.value = 0
self.aces = 0
#ADDS CARDS TO HANDS ONCE DEALT
def add_card(self,card):
#ADDS CARD TO HAND
self.cards.append(card)
#HOLDS THE VALUE OF THE HAND
key = ''
key = card.split()
self.value += values[key[0]]
#ACCOUNT FOR ACE
if key[0] == 'Ace':
self.aces += 1
#KEEPS TRACK OF ACES; ADJUSTS VALUE FOR ACE WHEN APPROPARIATE
def adjust_for_ace(self,card):
if self.value > 21 and self.aces:
self.value -= 10
self.aces -= 1
class Chips:
def __init__(self):
self.total = 100
self.bet = 0
#ADD CHIPS TO TOTAL IF WIN
def win_bet(self):
self.total += self.bet
#TAKE AWAY CHIPS FORM TOTAL IF LOSE
def lose_bet(self):
self.total -= self.bet
#TAKE BET FROM USER
def take_bet(Chips):
while True:
try:
Chips.bet = int(input("How many chips do you want to bet?: "))
except:
print("There was an error! Enter an integer!\n")
continue
else:
if Chips.bet > Chips.total:
print("You don't have enough chips!\n")
else:
print("Your bet is {} chips\n".format(Chips.bet))
break
#IF PLAYER CHOOSES TO HIT
def hit(deck,hand):
#USE IN hit_or_stay function; ADDS CARD DEALT FROM DECK TO THE HAND and ADJUSTS FOR ACES
Hand.add_card(deck.deal())
Hand.adjust_for_ace()
#DETERMINE WHETHER PLAYER WANTS TO HIT OR STAY
def hit_or_stay(deck,hand):
global playing #controls upcoming loop
while True:
h_or_s = raw_input("Would you like to hit or stay? Enter 'hit' or 'stay': ")
if h_or_s[0].lower() == "h":
hit(deck,hand)
elif h_or_s[0].lower() == "s":
playing = False
else:
print("\nThere was an error. Try again.\n")
continue
break
def show_some(player,dealer):
print("Dealer's Hand:")
print(dealer.cards[0])
print("< card hidden >\n")
print("\nPlayer's hand value: {}".format(player.value))
print("Player's Hand:", *player.cards, sep='\n')
def show_all(player,dealer):
print("\nDealer's hand value: {}".format(dealer.value))
print("\nDealer's Hand:", *dealer.cards, sep='\n')
print("\nPlayer's hand value: {}\n".format(player.value))
print("Player's Hand:", *player.cards, sep='\n')
#GAME ENDING FUNCTIONS
def player_busts(player,dealer,Chips):
#PRINT PLAYER BUSTS; TAKE AWAY CHIPS BET FROM TOTAL CHIPS
print("Dealer's hand value: {}\n Player's hand value: {}\n".format(dealer_hand.value,player_hand.value))
print("Player busts! Dealer Wins\n")
Chips.lose_bet()
print("You lost {} chips!\n You have {} chips remaining.".format(Chips.bet,Chips.total))
def player_wins(player,dealer,Chips):
print("Dealer's hand value: {}\n Player's hand value: {}\n".format(dealer_hand.value,player_hand.value))
print("Player wins!\n")
Chips.win_bet()
print("You won {} chips!\n You have {} chips remaining.".format(Chips.bet,Chips.total))
def dealer_busts(player,dealer,Chips):
print("Dealer's hand value: {}\n Player's hand value: {}\n".format(dealer_hand.value,player_hand.value))
print("Dealer busts! Player wins!\n")
Chips.lose_bet()
print("You won {} chips!\n You have {} chips remaining.".format(Chips.bet,Chips.total))
def dealer_wins(player,dealer,Chips):
print("Dealer's hand value: {}\n Player's hand value: {}\n".format(dealer_hand.value,player_hand.value))
print("Dealer wins!\n")
Chips.lose_bet()
print("You lost {} chips!\n You have {} chips remaining.".format(Chips.bet,Chips.total))
def push(player,dealer,Chips):
print("Player and Dealer tie, its a push!\n")
#GAMEPLAY
while True:
print("Welcome to Black Jack. Get as close to 21 as you can without going over 21.\n")
print("Dealer hits until he reaches 17. Aces count as 1 or 11\n")
#create an instance of Deck class and print the deck
game_deck = Deck()
#shuffle and print the deck
game_deck.shuffle()
#CREATE PLAYER HAND AND DEAL TWO CARDS
player_hand = Hand()
player_hand.add_card(game_deck.deal())
player_hand.add_card(game_deck.deal())
#CREATE DEALER HAND AND DEAL TWO CARDS
dealer_hand = Hand()
dealer_hand.add_card(game_deck.deal())
dealer_hand.add_card(game_deck.deal())
#TAKE BET FROM PLAYER
#player_chips = take_bet(Chips())
#SHOW ONE OF DEALER'S CARDS AND ALL OF PLAYER'S CARDS
show_some(player_hand,dealer_hand)
while playing: #THIS IS WHERE THE NAME ERROR OCCURS!!
if player_hand.value < 21:
#PLAYER CHOOSES HIT OR STAY
hit_or_stay(game_deck(),player_hand)
#SHOW PLAYERS CARDS AND KEEP ONE DEALER CARD HIDDEN
show_some(player_hand,dealer_hand)
NameError：名称“正在播放”未定义
答案 0 :(得分：0)
问题在于playing是在hit_or_stay中定义的，直到{em> 之后，while循环才被调用。
将playing定义为True以开始，或包含一个明确的break条件
while True:
print("Welcome to Black Jack. Get as close to 21 as you can without going over 21.\n")
print("Dealer hits until he reaches 17. Aces count as 1 or 11\n")
# ~snip~
# define here
playing = True
while playing:
# rest of your code
此外，看起来hit_or_stay 中也有一个while循环。我建议您看一下到目前为止的代码结构，甚至可能对其进行重构。除了break中的hit_or_stay，也许您可以return playing：
def hit_or_stay(deck,hand):
# no need for global playing anymore, as you return the proper bool
h_or_s = raw_input("Would you like to hit or stay? Enter 'hit' or 'stay': ")
if h_or_s[0].lower() == "h":
hit(deck,hand)
return True
elif h_or_s[0].lower() == "s":
return False
else:
raise ValueError("\nThere was an error. Try again.\n")
playing = True
while playing:
try:
playing = hit_or_stay(deck, hand)
# Catch the error for unexpected input and retry
except ValueError as e:
print(e)
continue
答案 1 :(得分：0)
global不会创建变量，而是defining the existing variable as global。因此，您试图声明某个变量是全局变量（但仍不存在），然后调用它。所以你会得到一个错误。
请不要在Python中使用global！在99.999％的情况下，您可以轻松替换代码而无需任何全局变量！例如，在代码的这一部分之后添加playing = True：
#GAMEPLAY
while True:
print("Welcome to Black Jack. Get as close to 21 as you can without going over 21.\n")
print("Dealer hits until he reaches 17. Aces count as 1 or 11\n")
#create an instance of Deck class and print the deck
game_deck = Deck()
#shuffle and print the deck
game_deck.shuffle()