On Thu, Feb 27, 2014 at 2:47 PM, 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?
x += y is meant to be equivalent, except possibly in-place and more efficient, than x = x + y. If you skip the assignment, and that assignment is meaningful to whatever the left side may be (e.g. assigning to a descriptor or something that invokes __setitem__ or __setattr__), then the operation is not equivalent. -- https://mail.python.org/mailman/listinfo/python-list
