title: Retrieving consumer group offsets in kafka using python library
body: <p>I have python script and I need to retrieve the current consumer group offset for a set of consumers reading from a kafka topic, using a kafka1 broker cluster. These are native kafka consumers that store the offset in the kafka cluster, not in zookeeper.</p>
  
  <p>The script itself does not need to consume any messages, just read the current offset for other consumers. I realise it is possible to do this with <code>kafka-consumer-groups.sh</code> but ideally I want to avoid relying on shell commands.</p>
  
  <p>I can already do this utilising the <code>dpkp/kafka-python</code> client, but only by creating a consumer and assigning it to the group, which then affects the existing consumers using that group by de-allocating some partitions. I need the script to be entirely passive, not performing any action that will interrupt the other consumers.</p>