On Fri, May 31, 2013 at 1:02 AM, Ethan Furman <et...@stoneleaf.us> wrote: > On 05/30/2013 05:58 AM, Chris Angelico wrote: >> If you iterate from 1000 to 173, you get nowhere. This is the expected >> behaviour; this is what a C-style for loop would be written as, it's >> what range() does, it's the normal thing. Going from a particular >> starting point to a particular ending point that's earlier than the >> start results in no iterations. The alternative would be an infinite >> number of iterations, which is far far worse. > > If the bug is the extra three zeros (maybe it should have been two), then > silently skipping the loop is the "far, far worse" scenario. With the > infinite loop you at least know something went wrong, and you know it pretty > darn quick (since you are testing, right? ;).
You're assuming you can casually hit Ctrl-C to stop an infinite loop, meaning that it's trivial. It's not. Not everything lets you do that; or possibly halting the process will halt far more than you intended. What if you're editing live code in something that's had uninterrupted uptime for over a year? Doing nothing is much safer than getting stuck in an infinite loop. And yes, I have done exactly that, though not in Python. Don't forget, your start/stop figures mightn't be constants, so you might not see it in testing. I can't imagine ANY scenario where you'd actually *want* the infinite loop behaviour, while there are plenty where you want it to skip the loop, and would otherwise have to guard it with an if. ChrisA -- http://mail.python.org/mailman/listinfo/python-list
