“无”出现在 output 中，我不知道为什么

Question

so I'm trying to build a hangman game in python. I've moreorless finished already but I can't figure out what in my code is causing the "None" to show up. I've read it's due to printing 'empty' data resulting in "None" showing up. I've tried removing the 'print' section individually but sometimes the programme doesn't run (Jupyter Notebook) which I don't really understand.

I'm looking to just remove the None output (it appears only after my first input). Thanks!

Image output

def get_word():
    wordlist = open("wordlist.txt").readlines()
    word = random.choice(wordlist) # this makes 'word' get a random choice from wordlist.txt
    return word.upper() #this sets all the text uppercase

#the get_word function should select a random value from the wordlist.txt file and set it to UPPER CASE

def play(word):
    word_length = len(word)-1
    word_completion = "_" * word_length
    guessed = False 
    guessed_letters = []
    wrong_guesses = 0
    print("Let's play hangman!")
    print("The word is", word_length, "letters long. You have 6 guesses")
    print(word_completion)
    while not guessed and wrong_guesses <= 6: 
        guess = input("Please guess a latter or word: ").upper()
        if len(guess) == 1 and guess.isalpha():
            if guess in guessed_letters:
                print("You already guessed this letter!", guess)
            elif guess not in word:
                print(guess, "is not in the word.")
                wrong_guesses = wrong_guesses + 1
                guessed_letters.append(guess)
                print("Incorrect guesses =", wrong_guesses)
                print("Letters already guessed: ", guessed_letters)
                
            else:
                print("Good job,", guess, "is in the word")
                guessed_letters.append(guess)
                print("Incorrect guesses =", wrong_guesses)
                print("Letters already guessed: ", guessed_letters)
                
                word_as_list = list(word_completion)
                indices = [i for i, letter in enumerate(word) if letter == guess]
                for index in indices:
                    word_as_list[index] = guess
                word_completion = "".join(word_as_list)
                if  "_" not in word_completion:
                    guessed = True 
                    
        elif len(guess) == len(word) and guess.isalpha():
            if guess in guessed_letters:
                print("You already guessed the word", guess)
                print("Incorrect guesses =", wrong_guesses)
                print("Letters already guessed: ", guessed_letters)
                
            elif guess != word:
                print(guess, "is not in the word.")
                wrong_guesses = wrong_guesses + 1 
                guessed_letters.apppend(guess)
            else:
                guessed = True
                word_completion = word
            
        else: 
            print("Not a valid guess.")
        print(print_graphics(wrong_guesses))
        print(word_completion)
        
    if guessed:
        print("Congrats, you guessed correctly, victory!")
    else:
        print("Sorry you lost, the word was", word)
        
        
def print_graphics(wrong_guesses):
    # list of possible body parts
    body_parts = ['  O     |', '  |     |',' /|     |', ' /|\    |', ' /      |', ' / \    |']
    
    lines = 4 if wrong_guesses != 0 else 5
    # check number provided is usable
    if 0 <= wrong_guesses <= 6:
        print('  +-----+')  # print top of frame
        print('  |     |')
    
        # print the correct body parts for current state
        if wrong_guesses > 0:
            if wrong_guesses > 1:
                print(body_parts[0])
                lines -= 1
            if wrong_guesses > 4:
                print(body_parts[3])
                lines -= 1
            print(body_parts[wrong_guesses-1])

        for i in range(lines):
            print('        |')  # print the lines
        
        print('==========')  # print the floor        
            
def main():
    word = get_word()
    play(word)
    while input("Play again? - Y/N ").upper() == "Y":
        word = get_word()
        play(word)
        
if __name__ == "__main__":
     main()

Answer 1

print(print_graphics(wrong_guesses))

your print_graphics function is doing the printing, but does not return any value. The default return value is None . Just change to:

print_graphics(wrong_guesses)