如何使用Python使用Google Pub / Sub和Google Dataflow / Beam？

I'm new to Pub/Sub and Dataflow/Beam. I have done a task in Spark and Kafka, I want to do the same using Pub/Sub and Dataflow/Beam. From what I understood so far Kafka is similar to Pub/Sub and Spark is similar to Dataflow/Beam.I'm new to Pub/Sub and Dataflow/Beam. I have do