为什么这个局部整数不能修改全局常量？

Question

我一直在用Python制作这个Hangman游戏。问题在于play_hangman函数。每次出现猜测，常数"猜测"就增加1。我想让它打印出"%s猜测剩余!"，我从全局常数(max_guess)减去局部常数(guess)得到%s。然而，它似乎不起作用，当它应该向下递增时，它继续吐出"剩下6个猜测"。有什么建议吗?

   # CONSTANTS
MAX_GUESSES = 6
# GLOBAL VARIABLES 
secret_word = 'claptrap' 
letters_guessed = []
# From part 3b:
def word_guessed():
    '''
    Returns True if the player has successfully guessed the word,
    and False otherwise.
    '''
    global secret_word
    global letters_guessed
    for i in secret_word:
        if i in letters_guessed:
            continue
        else:
            return False        
    return True

def print_guessed():
    '''
    Prints out the characters you have guessed in the secret word so far
    '''
    global secret_word
    global letters_guessed
    blanklist = []
    for i in secret_word:
        if i in letters_guessed:
            blanklist.append(i)
        else:
            blanklist.append("-")
    blanklist_string = "".join(blanklist)
    return blanklist_string
def play_hangman():
    # Actually play the hangman game
    global secret_word
    global letters_guessed
    global MAX_GUESSES
    # Put the mistakes_made variable here, since you'll only use it in this function
    mistakes_made = 0
    guesses = 0
    guesses_left = MAX_GUESSES - guesses
    while word_guessed() is False:
        print print_guessed()
        print "%s guesses left!" % guesses_left
        letter_choice = raw_input("Choose a letter:")
        if letter_choice not in secret_word:
            mistakes_made += 1
            print "you have made %s mistakes" %mistakes_made
            print "sorry, that is not in the word"
        letters_guessed.append(letter_choice)
        guesses +=1
        print "you have made %s guesses" %guesses
        word_guessed()
    while word_guessed() is True:
        print "Congratulations! You win :)"
        break

Answer 1

不需要重新计算guesses_left。在每次迭代开始时，您必须执行guesses_left = MAX_GUESSES - guesses

Answer 2

您需要将guesses_left = MAX_GUESSES - guesses放入while word_guessed() is False:循环中。就像现在一样，您在设置guesses == 0时设置guesses_left = MAX_GUESSES - guesses，然后在循环中只更改guesses。这将保持guesses_left不变。