對於基數爲10的int，文字無效：''

Question

>>> n = ''.join(i for i in x if i.isdigit()) 
>>> n.isdigit() 
True 
>>> x.isdigit() 
False 

>>> previous = 0 
>>> next = 100 
>>> answer = 0 


>>> for i in range(0,100): 
...  answer += int(n[previous:next]) 
...  previous = next 
...  next += 100 
... 
Traceback (most recent call last): 
    File "<stdin>", line 2, in <module> 
ValueError: invalid literal for int() with base 10: '' 

爲什麼我會收到此錯誤？正如你所看到的n是數字..

Answer 1

n可能是數字，但在某個階段，你會超過n的長度，使得n[previous:next]根本不包含任何字符。空字符串''不能轉換爲int，因此錯誤會告訴整個故事：invalid literal for int() with base 10: ''。

>>> int('') 
Traceback (most recent call last): 
    File "<input>", line 1, in <module> 
ValueError: invalid literal for int() with base 10: ''