将二进制转换为十进制整数输出 [英] Converting binary to decimal integer output

问题描述

我需要将二进制输入转换为十进制整数.我知道如何从十进制转换为二进制:

I need to convert a binary input into a decimal integer. I know how to go from a decimal to a binary:

n = int(raw_input('enter a number: '))
print '{0:b}'.format(n)

我需要朝相反的方向走.我的教授说，当他检查我们的代码时，他将输入 11001 ，他应该会得到 25 .我已经仔细阅读了笔记，但不知道该怎么做.Google和其他互联网资源也没有太大帮助.

I need to go in the reverse direction. My professor said that when he checks our code, he is going to input 11001, and he should get 25 back. I've looked through our notes, and I cannot figure out how to do this. Google and other internet resources haven't been much help either.

最大的问题是我们不允许使用内置函数.我知道为什么我们不允许使用它们，但是这使这个问题变得更加困难，因为我知道Python有一个内置的二进制到十进制函数.

The biggest problem is that we are not allowed to use built-in functions. I understand why we are not allowed to use them, but it's making this problem much more difficult, since I know Python has a built-in function for binary to decimal.

推荐答案

您可以使用 int 并将基数设置为 2 (对于二进制):

You can use int and set the base to 2 (for binary):

>>> binary = raw_input('enter a number: ')
enter a number: 11001
>>> int(binary, 2)
25
>>>

---

但是，如果您不能像这样使用 int ，那么您始终可以这样做:

---

However, if you cannot use int like that, then you could always do this:

binary = raw_input('enter a number: ')
decimal = 0
for digit in binary:
    decimal = decimal*2 + int(digit)
print decimal

下面是一个演示:

>>> binary = raw_input('enter a number: ')
enter a number: 11001
>>> decimal = 0
>>> for digit in binary:
...     decimal = decimal*2 + int(digit)
...
>>> print decimal
25
>>>

这篇关于将二进制转换为十进制整数输出的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！