What are the alternatives to Python + Spark (pyspark)? I like Python, and I like Spark, but they don't fit very well together.  In particular,

it is very hard to use python functions in spark (have to create JVM binding for function in python)
it is hard to debug pyspark, with py4j in the middle

So I wonder if there are any alternatives to pyspark that supports python natively instead of via an adapter layer?
Reference
Try checking dask. It's a distributed library which is native with Python and it uses pandas and numpy. So its like using pandas with some wrapper for distribution computation.