Re: Infinitely nested containers

References	<931d12c0-12b3-4278-a9b9-1e2c32f138b3@googlegroups.com>
From	Ian Kelly <ian.g.kelly@gmail.com>
Date	2014-11-21 10:13 -0700
Subject	Re: Infinitely nested containers
Newsgroups	comp.lang.python
Message-ID	<mailman.16113.1416590068.18130.python-list@python.org> (permalink)

Show all headers | View raw

On Thu, Nov 20, 2014 at 10:54 PM, Gill Shen <gillarete@gmail.com> wrote:
> How is this behavior implemented under the hood? And why is this allowed at all? Is it just a curiosity or can you do something useful with it?

Reference cycles are common in Python and other OO languages. For
example, adding a widget to a window; the window contains references
to its child widgets, and it's probably useful for the widgets to know
what their parents are, so they would hold references back.

A list containing itself is similarly a reference cycle. I don't know
off-hand of any use for this specific case, but it's just a slightly
tighter cycle than normal.

Back to comp.lang.python | Previous | Next — Previous in thread | Find similar | Unroll thread

Thread

Infinitely nested containers Gill Shen <gillarete@gmail.com> - 2014-11-20 21:54 -0800
  Re: Infinitely nested containers Marko Rauhamaa <marko@pacujo.net> - 2014-11-21 09:00 +0200
    Re: Infinitely nested containers random832@fastmail.us - 2014-11-21 12:39 -0500
      Re: Infinitely nested containers Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-11-22 15:43 +1100
        Re: Infinitely nested containers Chris Angelico <rosuav@gmail.com> - 2014-11-22 15:50 +1100
          Re: Infinitely nested containers Rustom Mody <rustompmody@gmail.com> - 2014-11-21 21:02 -0800
            Re: Infinitely nested containers Chris Angelico <rosuav@gmail.com> - 2014-11-22 16:09 +1100
              Re: Infinitely nested containers Rustom Mody <rustompmody@gmail.com> - 2014-11-21 22:03 -0800
        Re: Infinitely nested containers Ethan Furman <ethan@stoneleaf.us> - 2014-11-22 11:50 -0800
          Re: Infinitely nested containers Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-11-23 16:59 +1100
            Re: Infinitely nested containers random832@fastmail.us - 2014-11-23 01:39 -0500
    Re: Infinitely nested containers Chris Angelico <rosuav@gmail.com> - 2014-11-22 04:47 +1100
    Re: Infinitely nested containers random832@fastmail.us - 2014-11-21 12:50 -0500
    Re: Infinitely nested containers Ian Kelly <ian.g.kelly@gmail.com> - 2014-11-21 11:37 -0700
    Re: Infinitely nested containers Zachary Ware <zachary.ware+pylist@gmail.com> - 2014-11-21 13:30 -0600
    Re: Infinitely nested containers Terry Reedy <tjreedy@udel.edu> - 2014-11-22 16:57 -0500
  Re: Infinitely nested containers Chris Angelico <rosuav@gmail.com> - 2014-11-21 18:03 +1100
  Re: Infinitely nested containers Ian Kelly <ian.g.kelly@gmail.com> - 2014-11-21 10:13 -0700

csiph-web