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Groups > comp.lang.python > #69822

Re: Mutable objects inside tuples - good or bad?

From Terry Reedy <tjreedy@udel.edu>
Subject Re: Mutable objects inside tuples - good or bad?
Date 2014-04-07 20:16 -0400
References <89df32f9-c8ae-4b7b-bfc4-01c574aabcae@googlegroups.com> <53410185.6050304@islandtraining.com> <5342C3AD.9080707@subsignal.org>
Newsgroups comp.lang.python
Message-ID <mailman.8987.1396916189.18130.python-list@python.org> (permalink)

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On 4/7/2014 11:26 AM, Paul Kölle wrote:

>  >>> c = (1,2,3)
>  >>> d = (1,2,3)
>  >>> c is d
> False

An implementation would be allowed to make that True, as it does for 
small ints and short strings that could be identifiers.

 >>> a = 'one'
 >>> b = 'one'
 >>> a == b; a is b
True
True

However, duplicate tuples are much rarer than duplicate identifier strings.

-- 
Terry Jan Reedy

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Thread

Mutable objects inside tuples - good or bad? John Ladasky <john_ladasky@sbcglobal.net> - 2014-04-05 23:53 -0700
  Re: Mutable objects inside tuples - good or bad? Gary Herron <gary.herron@islandtraining.com> - 2014-04-06 00:25 -0700
  Re: Mutable objects inside tuples - good or bad? Devin Jeanpierre <jeanpierreda@gmail.com> - 2014-04-06 00:55 -0700
    Re: Mutable objects inside tuples - good or bad? Rustom Mody <rustompmody@gmail.com> - 2014-04-06 08:07 -0700
  Re: Mutable objects inside tuples - good or bad? Chris Angelico <rosuav@gmail.com> - 2014-04-06 18:25 +1000
  Re: Mutable objects inside tuples - good or bad? Devin Jeanpierre <jeanpierreda@gmail.com> - 2014-04-06 04:01 -0700
  Re: Mutable objects inside tuples - good or bad? Paul Kölle <paul@subsignal.org> - 2014-04-07 17:26 +0200
  Re: Mutable objects inside tuples - good or bad? Chris Angelico <rosuav@gmail.com> - 2014-04-08 01:44 +1000
  Re: Mutable objects inside tuples - good or bad? Paul Kölle <paul@subsignal.org> - 2014-04-07 21:46 +0200
  Re: Mutable objects inside tuples - good or bad? Chris Angelico <rosuav@gmail.com> - 2014-04-08 08:47 +1000
  Re: Mutable objects inside tuples - good or bad? Terry Reedy <tjreedy@udel.edu> - 2014-04-07 20:16 -0400
    Re: Mutable objects inside tuples - good or bad? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-04-08 02:53 +0000

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