is implemented with id ?

Aahz aahz at pythoncraft.com
Sat Nov 3 20:41:28 CET 2012


[got some free time, catching up to threads two months old]

In article <50475822$0$6867$e4fe514c at news2.news.xs4all.nl>,
Hans Mulder  <hansmu at xs4all.nl> wrote:
>On 5/09/12 15:19:47, Franck Ditter wrote:
>>
>> - I should have said that I work with Python 3. Does that matter ?
>> - May I reformulate the queston : "a is b" and "id(a) == id(b)"
>>   both mean : "a et b share the same physical address". Is that True ?
>
>Yes.
>
>Keep in mind, though, that in some implementation (e.g.  Jython), the
>physical address may change during the life time of an object.
>
>It's usually phrased as "a and b are the same object".  If the object
>is mutable, then changing a will also change b.  If a and b aren't
>mutable, then it doesn't really matter whether they share a physical
>address.

That last sentence is not quite true.  intern() is used to ensure that
strings share a physical address to save memory.
-- 
Aahz (aahz at pythoncraft.com)           <*>         http://www.pythoncraft.com/

"....Normal is what cuts off your sixth finger and your tail..."  --Siobhan


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