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Re: Inner workings of this Python feature: Can a Python data structure reference itself?

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On Sat, May 2, 2015 at 2:17 PM, Tim Chase <python.list@tim.thechases.com> wrote:
> If you know that you're creating such cyclical structures, it's best
> to manually unlink them before freeing them:
>
>   lst = []
>   lst.append(lst) # create the cycle
>   lst[:] = []   # break the cycle
>   # or lst.remove(lst) # though this takes more care
>   del lst

In general, this shouldn't be necessary. I believe that reference
cycles are guaranteed to be cleaned up in all major implementations of
Python, except that in CPython prior to version 3.4 reference cycles
containing objects with finalizers would not be collected. So the
better advice would be "don't use finalizers in reference cycles if
you need compatibility with Python 3.3 or earlier."

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Inner workings of this Python feature: Can a Python data structure reference itself? vasudevram <vasudevram@gmail.com> - 2015-05-02 13:02 -0700
  Re: Inner workings of this Python feature: Can a Python data structure reference itself? Tim Chase <python.list@tim.thechases.com> - 2015-05-02 15:17 -0500
    Re: Inner workings of this Python feature: Can a Python data structure reference itself? vasudevram <vasudevram@gmail.com> - 2015-05-02 14:07 -0700
    Re: Inner workings of this Python feature: Can a Python data structure reference itself? Cecil Westerhof <Cecil@decebal.nl> - 2015-05-02 23:06 +0200
      Re: Inner workings of this Python feature: Can a Python data structure reference itself? MRAB <python@mrabarnett.plus.com> - 2015-05-03 00:07 +0100
      Re: Inner workings of this Python feature: Can a Python data structure reference itself? Tim Chase <python.list@tim.thechases.com> - 2015-05-02 20:57 -0500
      Re: Inner workings of this Python feature: Can a Python data structure reference itself? Ian Kelly <ian.g.kelly@gmail.com> - 2015-05-02 22:29 -0600
  Re: Inner workings of this Python feature: Can a Python data structure reference itself? Tim Chase <python.list@tim.thechases.com> - 2015-05-02 15:10 -0500
  Re: Inner workings of this Python feature: Can a Python data structure reference itself? Terry Reedy <tjreedy@udel.edu> - 2015-05-02 19:17 -0400
    Re: Inner workings of this Python feature: Can a Python data structure reference itself? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-05-03 21:10 +1000
    Re: Inner workings of this Python feature: Can a Python data structure reference itself? vasudevram <vasudevram@gmail.com> - 2015-05-03 05:59 -0700
      Re: Inner workings of this Python feature: Can a Python data structure reference itself? vasudevram <vasudevram@gmail.com> - 2015-05-03 06:05 -0700
      Re: Inner workings of this Python feature: Can a Python data structure reference itself? Chris Angelico <rosuav@gmail.com> - 2015-05-03 23:08 +1000
        Re: Inner workings of this Python feature: Can a Python data structure reference itself? vasudevram <vasudevram@gmail.com> - 2015-05-03 08:46 -0700
  Re: Inner workings of this Python feature: Can a Python data structure reference itself? Ian Kelly <ian.g.kelly@gmail.com> - 2015-05-02 22:43 -0600
  Re: Inner workings of this Python feature: Can a Python data structure reference itself? Chris Angelico <rosuav@gmail.com> - 2015-05-03 15:46 +1000
  Re: Inner workings of this Python feature: Can a Python data structure reference itself? vasudevram <vasudevram@gmail.com> - 2015-05-03 03:52 -0700

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