Python bin() 和前导零

Question

As of Python 3 the leading zeros are excluded in a bin() conversion.

I am trying to manipulate a value and re-arrange the bits so I can decode an offset but after the conversion I am loosing the leading zeros from the value.

Which would be the best way to do that without losing the leading zeros?

Here is the code:

bytefeed = 0x0229  # which becomes 0x2902

def decodebytes(bytefeed, negative = True):

    rearrangedbits = list()
    reversed_dat.extend([bytefeed[1], bytefeed[0]])
    reversed_datdec = int.from_bytes(reversed_dat, byteorder='big', signed=False)
    bitfield2 = list(bin(reversed_datdec)[2:])
    rearrangedbits += bitfield2[4:10]
    rearrangedbits += bitfield2[0:4]
    rearrangedbits += bitfield2[10:17]
    bitfieldec2 = int("".join(map(str, rearrangedbits)),2)
    decovaroffset = finaloffset - bitfieldec2

    print(bitfield2)
    return decovaroffset

the result of the bitfield2 is:

['1', '0', '1', '0', '0', '1', '0', '0', '0', '0', '0', '0', '1', '0']

Should be:

['0', '0', '1', '0', '1', '0', '0', '1', '0', '0', '0', '0', '0', '0', '1', '0']

zfill() is not an option here as the padding will affect the offset if the variables does not have leading zero.

Answer 1

seems that zfill() fixes the issue for the list as i had previously misunderstood the usage..

so

bitfield2 = list(bin(reversed_datdec)[2:])

should be

bitfield2 = list(bin(reversed_datdec)[2:].zfill(16))