How can I, in python, iterate over multiple 2d lists at once, cleanly?

Question

If I\'m making a simple grid based game, for example, I might have a few 2d lists. One might be for terrain, another might be for objects, etc. Unfortunately, when I need to ite

Answer 1

for d1 in alist
   for d2 in d1
      if d2 = "whatever"
          do_my_thing()