Python for loops aren’t actually bounded: if the iterator you’re looping over doesn’t terminate then neither will the loop. It also only calls the iterator’s next() method once per loop, so it’s possible for the body of a loop to affect future iterations by mutating the iterator.

You’re right, of course. I had completely forgotten that.

I saw this before you deleted it, and i just wanted to say that I would much rather compile to tail recursion than a while loop, but I generally try to avoid explicit mutation (being a scheme guy)