On Sun, May 4, 2014 at 6:44 PM, Dave Angel <da...@davea.name> wrote: > C Smith <illusiontechniq...@gmail.com> Wrote in message: >> Sorry. >> >> I meant for example: >> list1 = [1,2,3] >> list2 = [3,4,5] >> >> newList = list1 + list2 >> >> versus >> >> for x in list2: >> list1.append(x) >> >> Which is the preferred way to add elements from one list to another? > > Thank you for switching to text mail. > > These examples still aren't equivalent. But in any similar > example, if list2 is type list, then avoid the list. Use either > extend, or the equivalent += . And if you aren't permitted to > change list1, you should use += .... > DaveA >
Lurking here. I am confused by "avoid the list". What does that mean? Also, you say extend and += are equivalent, yet say " if you aren't permitted to change list1, you should use +=" If they are equivalent, why choose one over the other? Doesn't += always change the left-hand side? Not being critical--just confused. Thanks, -Denis _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor