应该返回str的Python返回'None'

Question

I am working on a hangman program (it is a homework assignment) and this is the part where it tell the player what they have guessed so far. Here is my programming:

def getGuessedWord(secretWord, lettersGuessed):
theWord=''
for char in secretWord:
    if char not in lettersGuessed:
        char='_ '
        theWord+=char
    elif char in lettersGuessed:
        theWord+=char
    else:
        return theWord
print (getGuessedWord('apple', ['e', 't', 'i', 'p', 'r']

When I ask it to print out theWord I am expecting it to send out a combination of underscores and letters _ pp_ e , but instead is gives me None . I cannot figure out if my problem is where I placed theWord in line 2, or if it has to do with the else, or if it somewhere completely different.

Answer 1

You have to return something after successful execution of the entire for-loop:

def getGuessedWord(secretWord, lettersGuessed):
   theWord=''
   for char in secretWord:
      if char not in lettersGuessed:
         char='_ '
         theWord+=char
      elif char in lettersGuessed:
         theWord+=char
   return theWord #here, returning theWord
print (getGuessedWord('apple', ['e', 't', 'i', 'p', 'r']))

Answer 2

Just erase this else and fix the indentation. Like this:

def getGuessedWord(secretWord, lettersGuessed): 
    theWord=''
    for char in secretWord:
        if char not in lettersGuessed:
            char='_ '
            theWord+=char
        elif char in lettersGuessed:
            theWord+=char
    return theWord

print (getGuessedWord('apple', ['e', 't', 'i', 'p', 'r']

Actualy your function is returning nothing. It's because your return is never called. You just don't enter in this else. You wrote a if in statement and an elif not in, it means you covered all cases in these two statements, then have no sense write an else.