In grid.py there is a set of orientations, defined as follows:

orientations = [(1, 0), (0, 1), (-1, 0), (0, -1)]

I snooped around a bit, but I couldn't find what these mean. From my understanding they are showing where the current agent is looking in a 2D plane (Forward, Backward, Left, Right). I don't know though which is which. It would be nice to have this documented.

PS: I believe (0,1) is forward, (0,-1) back, (1,0) east and (-1,0) west, since that's how I've encountered it in literature. Not sure if this is the case here too though.