ValueError with randint

Question

我有這個奇怪的錯誤，我不知道它是什麼。 這是我的代碼：

def wordChoice(): 
    theme = themechoice 
    word = theme[randint(0, len(theme) - 1)] 

這是錯誤：

Traceback (most recent call last): 
    File "C:\Users\Andrei\Documents\USB Backup\Python\Hangman.py", line 31, in wordChoice 
      word = theme[randint(0, len(theme) - 1)] 
      File "C:\Users\Andrei\AppData\Local\Programs\Python\Python35-32\lib\random.py", line 218, in randint 
      return self.randrange(a, b+1) 
      File "C:\Users\Andrei\AppData\Local\Programs\Python\Python35-32\lib\random.py", line 196, in randrange 
      raise ValueError("empty range for randrange() (%d,%d, %d)" % (istart, istop, width)) 
     ValueError: empty range for randrange() (0,0, 0) 

我到處找，但我無法找到任何東西。如果這件事很明顯，我也很抱歉。

編輯：

之前，我設置主題，以這樣的：

def themeChoice(): 
    n = 0 
    for i in themes: 
     n += 1 
     print(str(n) + " - " + i) 
    themechoice = themesToThemes[themes[int(input("Type the number corresponding to your chosen theme: ")) - 1]] 
    print (themechoice) 

Answer 1

時theme爲空時會出現此錯誤。

>>> theme = [] 
>>> random.randint(0, len(theme)-1) 
Traceback (most recent call last): 
    File "<stdin>", line 1, in <module> 
    File "C:\Programming\Python 3.5\lib\random.py", line 218, in randint 
    return self.randrange(a, b+1) 
    File "C:\Programming\Python 3.5\lib\random.py", line 196, in randrange 
    raise ValueError("empty range for randrange() (%d,%d, %d)" % (istart, istop, width)) 
ValueError: empty range for randrange() (0,0, 0) 

確保theme試圖從中隨機選擇一個元素之前實際上已經在它的元素。另外，請考慮使用random.choice，而不是使用randint手動生成索引。