Denis Heidtmann <[email protected]> Wrote in message:
> On Sun, May 4, 2014 at 6:44 PM, Dave Angel <[email protected]> wrote:
>> C Smith <[email protected]> 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.
You're right to be confused; my fingers were confused typing my
last sentence. It should have ended:
... you should use + .
Likewise the previous thought should have said:
But in any similar
example, if list2 is type list, then
avoid the loop.
I've been trying to use a tablet to run a newsreader, and between
bugs in the reader and an over enthusiastic spell correction,
I'm ready to give up.
--
DaveA
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