Re: repeat items in a list

From	Peter Otten <__peter__@web.de>
Newsgroups	comp.lang.python
Subject	Re: repeat items in a list
Date	2016-03-30 17:52 +0200
Organization	None
Message-ID	<mailman.213.1459353139.28225.python-list@python.org> (permalink)
References	(2 earlier) <29bb9c16-eef4-4c00-9e41-ce8419405c29@googlegroups.com> <ndb50q$b8e$2@gioia.aioe.org> <1459173882.380114.561434386.096F166A@webmail.messagingengine.com> <ndersg$394$1@ger.gmane.org> <CAGgTfkOgcfMZ=CfvpdDVZ3wckTBsg8uHmv5to7BdiKZNyYuQiA@mail.gmail.com>

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Michael Selik wrote:

> I prefer itertools.chain.from_iterable to the sum trick.
> 
>>>> from itertools import chain
>>>> lst = list('abc')
>>>> list(chain.from_iterable([s]*3 for s in lst))
> ['a', 'a', 'a', 'b', 'b', 'b', 'c', 'c', 'c']

If you want to make this completely lazy:

>>> from functools import partial
>>> from itertools import repeat, chain
>>> items = list("abc")
>>> list(chain.from_iterable(map(partial(repeat, times=3), items)))
['a', 'a', 'a', 'b', 'b', 'b', 'c', 'c', 'c']

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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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