Path: csiph.com!fu-berlin.de!uni-berlin.de!not-for-mail
From: Chris Angelico <rosuav@gmail.com>
Newsgroups: comp.lang.python
Subject: Re: Storing a big amount of path names
Date: Fri, 12 Feb 2016 14:49:15 +1100
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References: <n9j94f$712$1@gioia.aioe.org> <56BD4DCD.4080401@mrabarnett.plus.com>
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On Fri, Feb 12, 2016 at 2:13 PM, MRAB <python@mrabarnett.plus.com> wrote:
> Apart from all of the other answers that have been given:
>
>>>> p1 = 'foo/bar'
>>>> p2 = 'foo/bar'
>>>> id(p1), id(p2)
> (982008930176, 982008930120)
>>>> d = {}
>>>> id(d.setdefault(p1, p1))
> 982008930176
>>>> id(d.setdefault(p2, p2))
> 982008930176
>
> The dict maps equal strings (dirnames) to the same string, so you won't have
> multiple copies.

Simpler to let the language do that for you:

>>> import sys
>>> p1 = sys.intern('foo/bar')
>>> p2 = sys.intern('foo/bar')
>>> id(p1), id(p2)
(139621017266528, 139621017266528)

ChrisA