I am working with Python3.2. I need to take a hex stream as an input and parse it at bit-level. So I used

bytes.fromhex(input_str)

to convert the string to actual bytes. Now how do I convert these bytes to bits?

解决方案

Another way to do this is by using the bitstring module:

>>> from bitstring import BitArray

>>> input_str = '0xff'

>>> c = BitArray(hex=input_str)

>>> c.bin

'0b11111111'

And if you need to strip the leading 0b:

>>> c.bin[2:]

'11111111'

The bitstring module isn't a requirement, as jcollado's answer shows, but it has lots of performant methods for turning input into bits and manipulating them. You might find this handy (or not), for example:

>>> c.uint

255

>>> c.invert()

>>> c.bin[2:]

'00000000'

etc.