Python猜词游戏Bug：仅错猜应扣血，却每次猜测都扣生命值

问题描述 #

编写的Python猜词游戏预期仅在用户猜错字母时扣除1点生命值，但实际无论猜对猜错，生命值都会减少1点。

原代码 #

import random
# Make a list of different animal or anything.
word_list = ["ardvark", "baboon", "camel"]


# Use the random module to randomly pick an animal in the list.
random_word = random.choice(word_list)


# print the choosen word.
print(random_word)


display = ["_" for _ in random_word]

lives = 6

# empty guess.
guess = ''
# empty guess list.

# while loop in display.
while "_" in display:
    # ask the user to guess a letter from the chosen word.
    guess = input("Guess a letter: ").lower()
    # get the range and the len of the chosen word.
    for i in range(len(random_word)):
        # if the letter(guess) is equal to one of the letter in the chosen word.
        if random_word[i] == guess:
            display[i] = random_word[i]
    if random_word != guess:
        lives -= 1
        print(lives)
    # print the display with the right letter.
    print(" ".join(display))

运行结果 #

RESULTS:
baboon
Guess a letter: b
5
b _ b _ _ _
Guess a letter: r
4
b _ b _ _ _
Guess a letter:

问题分析与修复 #

错误原因 #

核心问题在于生命值扣除的判断条件：

if random_word != guess:
    lives -= 1

这里是将整个随机单词和用户输入的单个字母做比较，显然除了单词长度为1的极端情况外，这个条件永远为True，导致每次循环都会扣除生命值，和用户是否猜对无关。

修复方案 #

将判断条件改为检查用户猜测的字母不在随机单词中时，才扣除生命值：

if guess not in random_word:
    lives -= 1
    print(lives)

修复后的完整代码 #

import random
# Make a list of different animal or anything.
word_list = ["ardvark", "baboon", "camel"]


# Use the random module to randomly pick an animal in the list.
random_word = random.choice(word_list)


# print the choosen word.
print(random_word)


display = ["_" for _ in random_word]

lives = 6

# empty guess.
guess = ''
# empty guess list.

# while loop in display.
while "_" in display:
    # ask the user to guess a letter from the chosen word.
    guess = input("Guess a letter: ").lower()
    # get the range and the len of the chosen word.
    for i in range(len(random_word)):
        # if the letter(guess) is equal to one of the letter in the chosen word.
        if random_word[i] == guess:
            display[i] = random_word[i]
    # 修改判断条件：仅当猜测的字母不在单词中时扣生命值
    if guess not in random_word:
        lives -= 1
        print(lives)
    # print the display with the right letter.
    print(" ".join(display))

内容的提问来源于stack exchange，提问作者DJ MASK