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Groups > comp.lang.python > #6300

Re: Puzzled by list-appending behavior

References <16c21256-48df-416a-971f-de49ca4cc981@x6g2000yqj.googlegroups.com>
Date 2011-05-26 17:20 +1000
Subject Re: Puzzled by list-appending behavior
From Chris Angelico <rosuav@gmail.com>
Newsgroups comp.lang.python
Message-ID <mailman.2111.1306394456.9059.python-list@python.org> (permalink)

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On Thu, May 26, 2011 at 2:46 PM, Uncle Ben <bgreen@nycap.rr.com> wrote:
> In playing with lists of lists, I found the following:
>
> (In 3.1, but the same happens also in 2.7)
>
> list = [1,2,3]

Ben Finney has already answered the main question, but as a side
point, I would generally avoid creating a variable called 'list'.
That's the name of the type (Python 2) or class (Python 3) of all
lists, so it might result in confusion if you have an actual list with
that name.

If you want the behaviour of joining two lists (or adding something to
a list) and saving the result elsewhere, you can use the plain
addition:

a=[1,2,3]
b=a+[[4,5,6]]

Note that you have to add a list, and it will append the contents of that list.

Chris Angelico

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Thread

Puzzled by list-appending behavior Uncle Ben <bgreen@nycap.rr.com> - 2011-05-25 21:46 -0700
  Re: Puzzled by list-appending behavior Ben Finney <ben+python@benfinney.id.au> - 2011-05-26 15:11 +1000
  Re: Puzzled by list-appending behavior Chris Rebert <clp2@rebertia.com> - 2011-05-25 22:17 -0700
  Re: Puzzled by list-appending behavior Chris Angelico <rosuav@gmail.com> - 2011-05-26 17:20 +1000
  Re: Puzzled by list-appending behavior Chris Angelico <rosuav@gmail.com> - 2011-05-26 17:23 +1000
  Re: Puzzled by list-appending behavior Uncle Ben <bgreen@nycap.rr.com> - 2011-05-26 00:33 -0700
  Re: Puzzled by list-appending behavior Chris Rebert <clp2@rebertia.com> - 2011-05-26 01:09 -0700
  Re: Puzzled by list-appending behavior MRAB <python@mrabarnett.plus.com> - 2011-05-26 16:58 +0100
    Re: Puzzled by list-appending behavior Tim Roberts <timr@probo.com> - 2011-05-26 23:34 -0700
      Re: Puzzled by list-appending behavior MRAB <python@mrabarnett.plus.com> - 2011-05-27 17:02 +0100
  Re: Puzzled by list-appending behavior Chris Angelico <rosuav@gmail.com> - 2011-05-27 02:04 +1000
  Re: Puzzled by list-appending behavior John Ladasky <ladasky@my-deja.com> - 2011-05-26 11:27 -0700
    Re: Puzzled by list-appending behavior Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-05-27 01:59 +0000
      Re: Puzzled by list-appending behavior Chris Angelico <rosuav@gmail.com> - 2011-05-27 13:24 +1000
        Re: Puzzled by list-appending behavior Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-05-27 03:52 +0000
          Re: Puzzled by list-appending behavior Chris Angelico <rosuav@gmail.com> - 2011-05-27 14:10 +1000
          RE: Puzzled by list-appending behavior "Prasad, Ramit" <ramit.prasad@jpmchase.com> - 2011-05-27 13:58 -0400
          Re: Puzzled by list-appending behavior Ethan Furman <ethan@stoneleaf.us> - 2011-05-27 11:56 -0700
  Re: Puzzled by list-appending behavior Terry Reedy <tjreedy@udel.edu> - 2011-05-26 14:44 -0400
  RE: Puzzled by list-appending behavior "Prasad, Ramit" <ramit.prasad@jpmchase.com> - 2011-05-26 15:34 -0400
  Re: Puzzled by list-appending behavior Terry Reedy <tjreedy@udel.edu> - 2011-05-26 17:36 -0400

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