Convert AD objectGUID bytes to readable string

def objectGUIDAsString(bytes):
        """
        Returns an AD objectGUID as a human-readable string.  Takes into consideration big-endian formatting as follows:
        <reversed first four bytes>-<reversed second two bytes>-<reversed third two bytes>-<normal fourth two bytes>-<normal last 6 bytes>
        """

        ## python-ldap reads AD objectGUIDs incorrectly. Unpack each byte from the objectGUID as an integer, then translate back to hex and order correctly
        result =""
        byteIntVals=struct.unpack('!BBBBBBBBBBBBBBBB',bytes)
        for byteInt in byteIntVals:
            result = result + hex(byteInt).replace("0x",",")
        resultByteList=result[1:].split(",")

        #Prepend zero to single-digit values in byte list.
        for strByte in resultByteList:
            if len(strByte) == 1:
                resultByteList[resultByteList.index(strByte)] = "0" + strByte

        return resultByteList[3] + resultByteList[2] + resultByteList[1] + resultByteList[0] + "-" \
               + resultByteList[5] + resultByteList[4] + "-" \
               + resultByteList[7] + resultByteList[6] + "-" \
               + resultByteList[8] + resultByteList[9] + "-" \
               + resultByteList[10] + resultByteList[11] + resultByteList[12] + resultByteList[13] + resultByteList[14] + resultByteList[15]