title: kafka-python publish to all consumers
body: <p>Is there a way to publish a message to all the partitions?
  I am using kafka-python==1.4.3.</p>
  
  <p>Understood from the documentation that</p>
  
  <blockquote>
    <p>key (optional) – a key to associate with the message. Can be used to
    determine which partition to send the message to. If partition is None
    (and producer’s partitioner config is left as default), then messages
    with the same key will be delivered to the same partition (but if key
    is None, partition is chosen randomly). Must be type bytes, or be
    serializable to bytes via configured key_serializer.</p>
  </blockquote>
  
  <p>but was not able to find any clue if the message can be published to all partitions.</p>