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Re: repeat items in a list

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From Mark Lawrence <breamoreboy@yahoo.co.uk>
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Subject Re: repeat items in a list
Date Sat, 26 Mar 2016 23:28:59 +0000
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On 26/03/2016 22:12, beliavsky--- via Python-list wrote:
> I can create a list that has repeated elements of another list as follows:
>
> xx = ["a","b"]
> nrep = 3
> print xx
> yy = []
> for aa in xx:
>      for i in range(nrep):
>          yy.append(aa)
> print yy
>
> output:
> ['a', 'b']
> ['a', 'a', 'a', 'b', 'b', 'b']
>
> Is there a one-liner to create a list with repeated elements?
>

yy = [aa for aa in xx for _ in range(nrep)]

I suggest that you try this sort of the thing at an interactive prompt, 
it's a great way to learn.

You might also want to take a look at the itertools module 
https://docs.python.org/3/library/itertools.html.  This is often used in 
building structures like the ones you've been asking about today.  To me 
it is the Swiss Army Knife of the stdlib.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence

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Thread

repeat items in a list beliavsky@aol.com - 2016-03-26 15:12 -0700
  Re: repeat items in a list Cameron Simpson <cs@zip.com.au> - 2016-03-27 10:05 +1100
  Re: repeat items in a list Erik <python@lucidity.plus.com> - 2016-03-26 23:23 +0000
    Re: repeat items in a list beliavsky@aol.com - 2016-03-26 16:36 -0700
      Re: repeat items in a list Rob Gaddi <rgaddi@highlandtechnology.invalid> - 2016-03-28 17:30 +0000
        Re: repeat items in a list Chris Angelico <rosuav@gmail.com> - 2016-03-29 08:25 +1100
          Re: repeat items in a list Antonio Caminero Garcia <tonycamgar@gmail.com> - 2016-03-29 01:43 -0700
        Re: repeat items in a list Erik <python@lucidity.plus.com> - 2016-03-28 23:14 +0100
  Re: repeat items in a list Mark Lawrence <breamoreboy@yahoo.co.uk> - 2016-03-26 23:28 +0000
    Re: repeat items in a list beliavsky@aol.com - 2016-03-26 16:54 -0700
      Re: repeat items in a list Paul Rubin <no.email@nospam.invalid> - 2016-03-26 22:35 -0700
  Re: repeat items in a list Antonio Caminero Garcia <tonycamgar@gmail.com> - 2016-03-27 01:02 -0700
    Re: repeat items in a list Antonio Caminero Garcia <tonycamgar@gmail.com> - 2016-03-27 01:30 -0700
    Re: repeat items in a list Jussi Piitulainen <jussi.piitulainen@helsinki.fi> - 2016-03-27 14:09 +0300
  Re: repeat items in a list larudwer <larudwer@freenet.de> - 2016-03-27 11:52 +0200
    Re: repeat items in a list Antonio Caminero Garcia <tonycamgar@gmail.com> - 2016-03-27 04:13 -0700
      Re: repeat items in a list larudwer <larudwer@freenet.de> - 2016-03-28 13:36 +0200
        Re: repeat items in a list Random832 <random832@fastmail.com> - 2016-03-28 10:04 -0400
        Re: repeat items in a list Vito De Tullio <vito.detullio@gmail.com> - 2016-03-29 23:25 +0200
        Re: repeat items in a list Michael Selik <michael.selik@gmail.com> - 2016-03-29 22:05 +0000
        Re: repeat items in a list Peter Otten <__peter__@web.de> - 2016-03-30 17:52 +0200

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