基数为10的int的文字无效：''

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: ''

为什么我收到此错误？如你所见，n是数字..

Answer 1

n可能是数字，但在某个阶段，您将超过n的长度，以致n[previous:next]根本不包含任何字符。空字符串''无法转换为int，因此错误告诉完整故事：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: ''