That's admittedly a pretty confusing example. I don't recommend ever iterating over multiple lists in a single comprehension. A mental breakdown is: For episod

That's admittedly a pretty confusing example. I don't recommend ever iterating over multiple lists in a single comprehension. A mental breakdown is: For episodes in episodes for planet in episode planets give me planet the binding of `planet` isn't evaluated until the end (left to right evaluation for the looping bits)