Re: Storing a big amount of path names

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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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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

Thread

Storing a big amount of path names Paulo da Silva <p_s_d_a_s_i_l_v_a_ns@netcabo.pt> - 2016-02-12 00:31 +0000
  Re: Storing a big amount of path names Chris Angelico <rosuav@gmail.com> - 2016-02-12 11:39 +1100
  Re: Storing a big amount of path names Ben Finney <ben+python@benfinney.id.au> - 2016-02-12 11:44 +1100
  Re: Storing a big amount of path names Tim Chase <python.list@tim.thechases.com> - 2016-02-11 19:13 -0600
    Re: Storing a big amount of path names Rob Gaddi <rgaddi@highlandtechnology.invalid> - 2016-02-12 02:17 +0000
  Re: Storing a big amount of path names MRAB <python@mrabarnett.plus.com> - 2016-02-12 03:13 +0000
  Re: Storing a big amount of path names Chris Angelico <rosuav@gmail.com> - 2016-02-12 14:49 +1100
    Re: Storing a big amount of path names Paulo da Silva <p_s_d_a_s_i_l_v_a_ns@netcabo.pt> - 2016-02-12 04:15 +0000
      Re: Storing a big amount of path names Chris Angelico <rosuav@gmail.com> - 2016-02-12 15:23 +1100
        Re: Storing a big amount of path names Paulo da Silva <p_s_d_a_s_i_l_v_a_ns@netcabo.pt> - 2016-02-12 04:45 +0000
          Re: Storing a big amount of path names Chris Angelico <rosuav@gmail.com> - 2016-02-12 16:02 +1100
            Re: Storing a big amount of path names Paulo da Silva <p_s_d_a_s_i_l_v_a_ns@netcabo.pt> - 2016-02-12 05:49 +0000
            Re: Storing a big amount of path names Steven D'Aprano <steve@pearwood.info> - 2016-02-12 16:51 +1100
        Re: Storing a big amount of path names Rob Gaddi <rgaddi@highlandtechnology.invalid> - 2016-02-12 17:05 +0000
          Re: Storing a big amount of path names Chris Angelico <rosuav@gmail.com> - 2016-02-13 04:18 +1100
          Re: Storing a big amount of path names Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-02-12 21:37 +0000
          Re: Storing a big amount of path names Ben Finney <ben+python@benfinney.id.au> - 2016-02-13 08:49 +1100
          Re: Storing a big amount of path names Matt Wheeler <funkyhat@gmail.com> - 2016-02-12 23:31 +0000
            Re: Storing a big amount of path names mkondrashin@gmail.com - 2016-02-13 12:19 -0800
  Re: Storing a big amount of path names srinivas devaki <mr.eightnoteight@gmail.com> - 2016-02-12 11:46 +0530

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