Overview

This document is a collection of best practices for Wrangler CSV parsing and cleansing of CSV files.

General Tips

• Parse CSV parse-as-csv should avoid using automatic header determination (parse-as-csv :col ‘\t’ false). On large files that are distributed across multiple partitions and header is no available to be set in different partitions.

• Sometimes a file looks fine, It could contain non-printable ASCII characters that usually don’t belong in CSV files. It can be hard to track these down. Use find-and-replace directive. `find-and-replace 's/\000-\007\013-\037\177-\377//g'.