The simplest way to obtain a CSV is to download the dataset, which is then consolidated in a single CSV file.
However if I understand your question correctly, you want to automatically export a single-CSV-file HDFS dataset. Unfortunately this is not yet natively supported, you'd need to add a Shell recipe to consolidate those files manually afterwards (and add the extension). The `.csv` extensions will be added in the upcoming 2.3 release of DSS.
Also, note that the out-s42* files are already in csv format. As compared to your request - they are split into several files (due to parallel processing) - they lack the ".csv" extension (upgrade to the soon to be released v2.3 to fix this)
But they should be readable by your downstream application.