从Python中的stdin读取整数

Question

我有以下代码，其中我从stdin中获取一个整数n，将其转换为二进制，反转二进制字符串，然后转换回整数并输出。

import sys

def reversebinary():

  n = str(raw_input())

  bin_n = bin(n)[2:]

  revbin = "".join(list(reversed(bin_n)))

  return int(str(revbin),2)

reversebinary()

但是，我收到此错误：

Traceback (most recent call last):   

File "reversebinary.py", line 18, in <module>

  reversebinary()   

File "reversebinary.py", line 14, in reversebinary

   bin_n = bin(n)[2:] 

TypeError: 'str' object cannot be interpreted as an index

我不确定是什么问题。

Answer 1

您正在将字符串传递给bin()函数：>>> bin('10')Traceback (most recent call last):&nbsp; File "<stdin>", line 1, in <module>TypeError: 'str' object cannot be interpreted as an index给它一个整数来代替：>>> bin(10)'0b1010'通过将raw_input()结果转换为int()：n = int(raw_input())提示：您可以通过给负片跨度轻松地反转字符串：>>> 'forward'[::-1]'drawrof'因此您可以将功能简化为：def reversebinary():&nbsp; &nbsp; n = int(raw_input())&nbsp; &nbsp; bin_n = bin(n)[2:]&nbsp; &nbsp; revbin = bin_n[::-1]&nbsp; &nbsp; return int(revbin, 2)甚至：def reversebinary():&nbsp; &nbsp; n = int(raw_input())&nbsp; &nbsp; return int(bin(n)[:1:-1], 2)

Answer 2

您想将输入转换为整数而不是字符串-它已经是字符串。所以这行：n&nbsp;=&nbsp;str(raw_input())应该是这样的：n&nbsp;=&nbsp;int(raw_input())

Answer 3

它是原始输入，即字符串，但您需要一个int：bin_n&nbsp;=&nbsp;bin(int(n))