for循环仅遍历第一个字母

Question

我的循环似乎遍历第一个字母，然后打破它应该遍历secretWord中的每个字母，例如，代码波纹管应该打印出“_pp_e”，但是它只打印“_”。我不明白，那个代码有什么问题？

def getGuessedWord(secretWord, lettersGuessed): 
    ''' 
    secretWord: string, the word the user is guessing 
    lettersGuessed: list, what letters have been guessed so far 
    returns: string, comprised of letters and underscores that represents 
     what letters in secretWord have been guessed so far. 
    ''' 
    # FILL IN YOUR CODE HERE... 
    for letter in secretWord: 
     if letter in lettersGuessed: 
      return letter 
     else: 
      return '_' 

print(getGuessedWord("apple", ['e', 'i', 'k', 'p', 'r', 's'])) 

Answer 1

您return从第一次迭代中的函数。 return结束函数，在那里然后，所以for循环也不会继续。

您需要在函数本身中建立返回值。建立结果字符串一个字符时，用一个列表来保存所有字符第一，然后在年底加入那些连成一个字符串：

def getGuessedWord(secretWord, lettersGuessed): 
    ''' 
    secretWord: string, the word the user is guessing 
    lettersGuessed: list, what letters have been guessed so far 
    returns: string, comprised of letters and underscores that represents 
     what letters in secretWord have been guessed so far. 
    ''' 
    guessed = [] 
    for letter in secretWord: 
     if letter in lettersGuessed: 
      guessed.append(letter) 
     else: 
      guessed.append('_') 
    return ''.join(guessed) 

如果你喜欢冒险，你甚至可以作出这样的一个list comprehension和做所有的工作在一个行：

def getGuessedWord(secretWord, lettersGuessed): 
    ''' 
    secretWord: string, the word the user is guessing 
    lettersGuessed: list, what letters have been guessed so far 
    returns: string, comprised of letters and underscores that represents 
     what letters in secretWord have been guessed so far. 
    ''' 
    return ''.join([l if l in lettersGuessed else '_' for l in secretWord]) 

两个版本产生预期的输出：

>>> print(getGuessedWord("apple", ['e', 'i', 'k', 'p', 'r', 's'])) 
_pp_e 

Answer 2

return关键字退出CA lling功能。这应该做的伎俩：

def getGuessedWord(secretWord, lettersGuessed): 

    result = '' 
    for letter in secretWord: 
     if letter in lettersGuessed: 
      result += letter 
     else: 
      result += '_' 
    return result 

print(getGuessedWord("apple", ['e', 'i', 'k', 'p', 'r', 's'])) 

在这里，你开始与一个空字符串作为结果，或者追加一个字母（如果它被列入名单）或下划线（如果不是），然后返回结果字符串。