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Re: Append to python List

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Date Thu, 9 May 2013 16:52:42 +1000
Subject Re: Append to python List
From Chris Angelico <rosuav@gmail.com>
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On Thu, May 9, 2013 at 4:36 PM, RAHUL RAJ <omrahulrajcse@gmail.com> wrote:
> output=[x for x in sample2 if x not in output]
>
> output=[]
> for x in sample2:
>   if x not in output:
>      output.append(x)

The first one constructs a list, then points the name 'output' at it.
The second one builds up a list, with 'output' pointing at it all the
way. Your first one is more like:

sample2 = [x+y for x in range(1,10) for y in range(1,10) if x!=y]
output=[]
_temp=[]
for x in sample2:
  if x not in output:
     _temp.append(x)
output=_temp

You may want to consider using a set, instead.

>>> {x+y for x in range(1,10) for y in range(1,10) if x!=y}
{3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17}

ChrisA

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Append to python List RAHUL RAJ <omrahulrajcse@gmail.com> - 2013-05-08 23:36 -0700
  Re: Append to python List Jussi Piitulainen <jpiitula@ling.helsinki.fi> - 2013-05-09 09:55 +0300
    Re: Append to python List 88888 Dihedral <dihedral88888@googlemail.com> - 2013-05-09 04:24 -0700
      Re: Append to python List Jussi Piitulainen <jpiitula@ling.helsinki.fi> - 2013-05-09 14:30 +0300
        Re: Append to python List 88888 Dihedral <dihedral88888@googlemail.com> - 2013-05-10 02:51 -0700
        Re: Append to python List Chris Angelico <rosuav@gmail.com> - 2013-05-09 21:49 +1000
          Re: Append to python List Anssi Saari <as@sci.fi> - 2013-05-11 18:47 +0300
            Re: Append to python List Chris Angelico <rosuav@gmail.com> - 2013-05-12 02:00 +1000
              Re: Append to python List 88888 Dihedral <dihedral88888@googlemail.com> - 2013-05-11 19:29 -0700
                Re: Append to python List Chris Angelico <rosuav@gmail.com> - 2013-05-12 12:40 +1000
          Re: Append to python List Jussi Piitulainen <jpiitula@ling.helsinki.fi> - 2013-05-12 09:02 +0300
  Re: Append to python List Chris Angelico <rosuav@gmail.com> - 2013-05-09 16:52 +1000
  Re: Append to python List Gary Herron <gary.herron@islandtraining.com> - 2013-05-08 23:54 -0700
    Re: Append to python List RAHUL RAJ <omrahulrajcse@gmail.com> - 2013-05-09 01:18 -0700
      Re: Append to python List RAHUL RAJ <omrahulrajcse@gmail.com> - 2013-05-09 01:19 -0700
      Re: Append to python List Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-05-09 11:14 +0000

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