Make a Pyspark script work on the latest version of spark

I have a PyScripts that they were running on spark 1.6, and stops working on spark2.4. the task will be to debogue this script and make it working on the lastest version of spark .

the scripts are reading parquet data from an S3 bucket and make a basic statistics about the files, the acript is running in a notebook on spark cluster

Acceptance Criteria
1- The Pysspark script running without any error on the pyspark cluster