I think what he meant is that beginners have an easier time with iterators and list indexing than with recursive techniques. An important target group for Python is beginners and non-programmers who do some programming in support of their primary work. That's why Guido values stack traces over tail call optimization. For Python, supporting beginners and amateurs is a higher goal than writing elegant functional code. Even for problems with elegant recursive solutions, beginners seem to find it easier to cobble together a more complicated loop-based solution than to find the simple recursive one. I know that makes everyone really sad :-( and maybe the long-term solution is to fix the school curriculum to teach programming earlier and better, but for now it's reality.
Good points. But favoring Python lists over recursion is like favoring chocolate over logging. However, I'm probably just playing gotcha here. My apologies to HN and Guido.
My more important point is that recursion is good for real world stuff.
Good points. But favoring Python lists over recursion is like favoring chocolate over logging.
No, no, it's not at all, not when you approach it from Guido's point of view. To him, the crucial question is, "What's the right way for beginners to process data?" Python and its built-in data structures support iteration and list indexing because that's how beginners do it. Python does not support tail calls because Guido thinks it's a mistake to teach recursion to beginners.
I think everyone is misunderstanding Guido's point because they just can't imagine anyone taking his point of view, so they imagine him saying something else. Joe Marshall even called Guido's main points (which he correctly identified, and then ungraciously caricatured) "a sideshow" and said the "true argument" is about the power of recursion. Sorry, Guido doesn't care about the power of recursion, because it isn't valuable to his target programmers, the programmers he wants to serve. He really thinks tail call support would be a very minor feature in Python because it's not important whether you can program in Python that way. He thinks complete stack trace information is very important because it makes things easy and transparent for beginners. That's what's important to Guido and, I would argue, to most Python programmers. When it comes to the future of Python, that's what matters, and Joe Marshall is the sideshow.
