Processing CSV files with Processing

A code example that shows how to read, modify and write .csv files with Processing.

I needed to proces some big (>1000000 rows) .csv files and change some data in one column based on time stored in another column. The first thought was to do this with MySQL/phpMyAdmin however importing large files like this takes time and you have to modify some PHP time-out settings.

Since Processing 2.0 working with .csv files is largely improved with the Table command.

Below the sketch that I’ve used to alter the table with a if/else condition. Pretty straightforward and fast (few seconds). Since it only runs one time there is no need to use setup() and draw() functions.