Manipulating a data structure in Pig/Hive

I'm not really sure how to phrase this question, so please redirect me if there is a better place for this question.

Right now I have a data structure, more or less organized like this:

I want my data to look like this:

Sorry for the images, apparently I can't use markdown to make these!

I realize my question is similar to this one, but ideally I would like to be able to do this in Pig, but knowing how to do it in Hive, R, Python, or Excel/LibreCalc would be useful/interesting too.

I'm not even sure what this kind of data manipulation is called, so directing me to some sort of general wiki page would be helpful.