python进制转换问题？

Question

一直对python的进制转换比较模糊。。
求讲解一下python的进制转换。百度过 但是没找到字母怎么转
比如

hexstr='5555555595555A65556AA696AA6666666955'
s=''
for i in xrange(len(hexstr)/2):
   ch=hexstr[i*2:i*2+2]
   b=bin(int(ch,16))[2:]
   b='0'*(8-len(b))+b
   s+=b
print s

010101010101010101010101010101011001010101010101010110100110010101010101011010101010011010010110101010100110011001100110011001100110100101010101

网上找到软件输出001101010011010100110101001101010011010100110101001101010011010100111001001101010011010100110101001101010100000100110110001101010011010100110101001101100100000101000001001101100011100100110110010000010100000100110110001101100011011000110110001101100011011000110110001110010011010100110101

看着都没错 但为什么有两种结果呢？？

Answer 1

不明白什么叫字母转2进制，如果你指的是2进制存储的话直接申明个buff流进行写入操作。如果是获取字符串的ascii码的话用encode转码