python - 如何检查输入是否为二进制格式(1 和 0)？

Question

我已经制作了一个程序，但是如果用户输入不是二进制格式，我想添加一个异常(exception)。我试过很多次添加异常(exception)，但我似乎无法让它工作。下面是程序代码。如果有人可以提供帮助，我将不胜感激。

import time
error=True
n=0
while n!=1:
    print"***Welcome to the Bin2Dec Converter.***\n"
    while error:
        try:
            bin2dec =raw_input("Please enter a binary number: ")
            error=False
        except NameError: 
            print"Enter a Binary number. Please try again.\n"
            time.sleep(0.5)
        except SyntaxError: 
            print"Enter a Binary number. Please try again.\n"
            time.sleep(0.5)


        #converts bin2dec
        decnum = 0 
        for i in bin2dec: 
            decnum = decnum * 2 + int(i)
            time.sleep(0.25)
        print decnum, "<<This is your answer.\n" #prints output

Answer 1

最好请求原谅。尝试使用 int(value, 2) 将其转换为整数:

while True:
    try:
        decnum = int(raw_input("Please enter a binary number: "), 2)
    except ValueError:
        print "Enter a Binary number. Please try again.\n"
    else:
        break

print decnum