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Date: Thu, 12 Jun 2014 13:58:27 +1000
Subject: Re: About python while statement and pop()
From: Chris Angelico <rosuav@gmail.com>
Cc: "python-list@python.org" <python-list@python.org>
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On Thu, Jun 12, 2014 at 1:40 PM, Vincent Vande Vyvre
<vincent.vandevyvre@swing.be> wrote:
> Le 12/06/2014 05:12, hito koto a =C3=A9crit :
>
>> Hello,all
>> I'm first time,
>>
>> I want to make a while statement which can function the same x.pop () an=
d
>> without the use of pop=E3=80=81how can i to do?
>>
>> i want to change this is code:
>>
>> def foo(x):
>>      y =3D []
>>      while x !=3D[]:
>>          y.append(x.pop())
>>      return y
>
> Something like that :
>
> def foo(x):
>     return reversed(x)

That doesn't do the same thing, though. Given a list x, the original
function will empty that list and return a new list in reverse order,
but yours will return a reversed iterator over the original list
without changing it. This is more accurate, but still not identical,
and probably not what the OP's teacher is looking for:

def foo(x):
    y =3D x[::-1]
    x[:] =3D []
    return y

If the mutation of x is unimportant, it can simply be:

def foo(x):
    return x[::-1]

ChrisA