def hamming_distance(bytes1: bytes, bytes2: bytes) -> int:
    """ Compute the Hamming distance between two bytes.
    The Hamming distance is the number of differing bits between the two
    bytes.
    >>> hamming_distance(b"this is a test", b"wokka wokka!!!")
    37
    """
    return sum([bin(c1 ^ c2).count('1') for (c1, c2) in zip(bytes1, bytes2)])