How to use the bitarray.bitdiff function in bitarray

def areImageSigsSimilar(sig1, sig2):
    """ Compare 2 image "signatures" and return True if they seem to come from a similar image, False otherwise. """
    return bitarray.bitdiff(sig1, sig2) < 100

def hamming_distance(self, fingerprint1, fingerprint2):
        """
        Return hamming distance between two given fingerprints.
        Hamming distance is the difference in the bits of two binary string.
        Files with fingerprints whose hamming distance are less tends to be more similar.
        """
        distance = bitdiff(fingerprint1, fingerprint2)
        result = int(distance)

        return result

def equalBitArrays(ba1, ba2):
        return bitdiff(ba1, ba2) == 0