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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def attribute_md5(self):
 """ The MD5 of all attributes is calculated by first generating a utf-8 string from each attribute and MD5-ing the concatenation of them all. Each attribute is encoded with some bytes that describe the length of each part and the type of attribute. Not yet implemented: List types (https://github.com/aws/aws-sdk-java/blob/7844c64cf248aed889811bf2e871ad6b276a89ca/aws-java-sdk-sqs/src/main/java/com/amazonaws/services/sqs/MessageMD5ChecksumHandler.java#L58k) """

        def utf8(str):
            if isinstance(str, six.string_types):
                return str.encode('utf-8')
            return str
        md5 = hashlib.md5()
        struct_format = "!I".encode('ascii')  # ensure it's a bytestring
        for name in sorted(self.message_attributes.keys()):
            attr = self.message_attributes[name]
            data_type = attr['data_type']

            encoded = utf8('')
            # Each part of each attribute is encoded right after it's
            # own length is packed into a 4-byte integer
            # 'timestamp' -> b'\x00\x00\x00\t'
            encoded += struct.pack(struct_format, len(utf8(name))) + utf8(name)
            # The datatype is additionally given a final byte
            # representing which type it is
            encoded += struct.pack(struct_format, len(data_type)) + utf8(data_type)
            encoded += TRANSPORT_TYPE_ENCODINGS[data_type]

            if data_type == 'String' or data_type == 'Number':
                value = attr['string_value']
            elif data_type == 'Binary':
                print(data_type, attr['binary_value'], type(attr['binary_value']))
                value = base64.b64decode(attr['binary_value'])
            else:
                print("Moto hasn't implemented MD5 hashing for {} attributes".format(data_type))
                # The following should be enough of a clue to users that
                # they are not, in fact, looking at a correct MD5 while
                # also following the character and length constraints of
                # MD5 so as not to break client softwre
                return('deadbeefdeadbeefdeadbeefdeadbeef')

            encoded += struct.pack(struct_format, len(utf8(value))) + utf8(value)

            md5.update(encoded)
        return md5.hexdigest()