On Fri, Feb 28, 2014 at 8:47 AM, Nick Timkovich <prometheus...@gmail.com> wrote: > On Thu, Feb 27, 2014 at 10:33 AM, Chris Angelico <ros...@gmail.com> wrote: >> >> On Fri, Feb 28, 2014 at 3:27 AM, Eric Jacoboni <eric.jacob...@gmail.com> >> wrote: >> > But, imho, it's far from being a intuitive result, to say the least. >> >> It's unintuitive, but it's a consequence of the way += is defined. If >> you don't want assignment, don't use assignment :) >> >> ChrisA > > > Where is `.__iadd__()` called outside of `list += X`? If the only > difference from `.extend()` is that it returns `self`, but the list was > already modified anyway, why bother with reassignment?
Not everything handles += that way. You can't mutate the integer 5 into 7 because someone had 5 in x and wrote "x += 2". So it has to reassign. Actually, integers just don't define __iadd__, but the principle applies. ChrisA -- https://mail.python.org/mailman/listinfo/python-list
