The true power of regular expressions emerges if we can use them not only for finding data, but also for manipulating data. GREL enables that and a lot of other functionality as well. It is a simple language designed for easily manipulating values. It consists of a set of built-in functions as well as several variables that are available through OpenRefine. We've briefly touched upon it in several recipes and we will show you the way to build your own GREL expressions here.
One place where GREL comes in handy especially is when you need to transform the values in your cells. You can either change cells in-place (by navigating to the respective column dropdown and then to Edit cells |