confluent-kafka python library is not working with ubutu14 and python3

Question

I am using "confluent-kafka==1.0.1". It works fine when I am using py3 and ubuntu18, but fails with py3 and ubuntu14. I get the following error.

Traceback (most recent call last):
File "/usr/local/lib/python3.4/dist-packages/metrics_agent/kafka_writer.py", line 147, in enqueue_for_topic
producer.produce(topic_name, msg, partition=_get_partition(producer, topic_name))
File "/usr/local/lib/python3.4/dist-packages/confluent_kafka/serializing_producer.py", line 168, in produce
raise KeySerializationError(se)
confluent_kafka.error.KeySerializationError: 
KafkaError{code=_KEY_SERIALIZATION,val=-162,str="'bytes' object has no attribute 'encode'"}
Exception KafkaError{code=_KEY_SERIALIZATION,val=-162,str="'bytes' object has no attribute 
'encode'"}
Traceback (most recent call last):
File "/usr/local/lib/python3.4/dist-packages/confluent_kafka/serializing_producer.py", line 166, in produce
key = self._key_serializer(key, ctx)
File "/usr/local/lib/python3.4/dist-packages/confluent_kafka/serialization/__init__.py", line 369, in __call__
return obj.encode(self.codec)
 AttributeError: 'bytes' object has no attribute 'encode'