Path: csiph.com!fu-berlin.de!uni-berlin.de!not-for-mail From: Michael Selik Newsgroups: comp.lang.python Subject: Re: repeat items in a list Date: Tue, 29 Mar 2016 22:05:16 +0000 Lines: 27 Message-ID: References: <8935d5dc-5e62-4fa8-8e8f-bd5b1787ee9f@googlegroups.com> <29bb9c16-eef4-4c00-9e41-ce8419405c29@googlegroups.com> <1459173882.380114.561434386.096F166A@webmail.messagingengine.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-Trace: news.uni-berlin.de W8owjvp63Dpfq3kY2a+AswmLlGg85XcyWKwlso8Ois4A== Return-Path: X-Original-To: python-list@python.org Delivered-To: python-list@mail.python.org X-Spam-Status: OK 0.008 X-Spam-Evidence: '*H*': 0.98; '*S*': 0.00; '[])': 0.09; 'lst': 0.09; '>>>': 0.15; "'a',": 0.16; "'b',": 0.16; "'c',": 0.16; '2016': 0.16; "['a',": 0.16; 'itertools': 0.16; 'received:io': 0.16; 'received:psf.io': 0.16; 'wrote:': 0.16; 'skip:l 30': 0.18; '>': 0.18; 'email addr:gmail.com>': 0.18; '>>>': 0.20; 'to:2**1': 0.21; 'import': 0.24; 'header:In-Reply-To:1': 0.24; 'subject:list': 0.26; 'message-id:@mail.gmail.com': 0.27; 'url:mailman': 0.30; 'url:python': 0.33; 'url:listinfo': 0.34; 'tue,': 0.34; 'received:google.com': 0.35; 'skip:i 20': 0.36; 'url:org': 0.36; 'received:209.85': 0.36; 'to:addr:python-list': 0.36; 'subject:: ': 0.37; 'turn': 0.37; 'received:209': 0.38; 'received:209.85.220': 0.38; 'url:mail': 0.40; 'to:addr:python.org': 0.40; 'mar': 0.65; 'sum': 0.69; 'trick.': 0.84 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:references:in-reply-to:from:date:message-id:subject:to; bh=+X4C6rTOYnUf4Sqs+aHGMc3xPVmzZjBUYe52rE8+8hk=; b=t5BqO+bbc9pqV/06OYknWFmujBcE8V6yOhRA4bO8tvwbA5p/cq994vaQIJuWfRIWDJ ViE6cqQk9FFZT3/BO+lZLnVHl0heY7vfPmiDj8n/gWREn9DLUTeYocR4qc2Oh5fSA706 eR3DzIh6R7/cZArV4gZIFtlMpPSE/GUeHSCJ6A9dMutO4jk0nYTyacGaqL9zTQHEZ/a0 elQb3zqYWLkxsAKzf0C0UASwSkeKNoUd7z2Og1RTTFKOjmWHHRyZhZb4eK0V9ia0V38V xWE3JdusN3ATRjLzQWvhR3eQJ0vaaO08kC7y8namP5w7C7sd/XLdX4ET9nQ5t37d81xt 6tmA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to; bh=+X4C6rTOYnUf4Sqs+aHGMc3xPVmzZjBUYe52rE8+8hk=; b=ZwW6kRSzNl+sT5FNbWFHrY7nTC2I9jV6rBDNoNixuThO5u+Q+6RRO7yjkhn4XWX76E TZWA5flJf4V9QMAfptzXgWwXcScwOtj22ZwHnAU1ft4eNsfX+oVGyl6zMnairL6oR3aS FidS2JzGgqqmoC34AtFRgVTKnIPgzgMzNzPZ5EvIg7LjOCEmyDfUaPL1AEZ4qVqIn0Mq ozSrOX5au7I+jGNVgbvwafLTQZLndneZyCG4vXD2ZKYZyVmdp4GFynX0egGBeqHyyQYt JyslnpNIdd2Z0VYA1Yp178E+pK9BUB7nZ/yNdFfOkZcxgVvdEFYwvByvCDkhoHSWUV63 iyog== X-Gm-Message-State: AD7BkJJbixuj8GzPxraEWW0oZYy1ibcuybe8IYfyS7dPwa1ZIlbjeWQKBG2NiyPxJKnxv97hAVUVJusmAZmZ1Q== X-Received: by 10.55.221.8 with SMTP id n8mr5830365qki.50.1459289126289; Tue, 29 Mar 2016 15:05:26 -0700 (PDT) In-Reply-To: X-Mailman-Approved-At: Wed, 30 Mar 2016 08:51:40 -0400 X-Content-Filtered-By: Mailman/MimeDel 2.1.21 X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: General discussion list for the Python programming language List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Xref: csiph.com comp.lang.python:106061 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'] On Tue, Mar 29, 2016 at 5:28 PM Vito De Tullio wrote: > Random832 wrote: > > > How do you turn ['a', 'c', 'b'] into ['a', 'a', 'a', 'c', 'c', 'c', 'b', > > 'b', 'b']? > > >>> sum([[e]*3 for e in ['a', 'c', 'b']], []) > ['a', 'a', 'a', 'c', 'c', 'c', 'b', 'b', 'b'] > > > -- > By ZeD > > -- > https://mail.python.org/mailman/listinfo/python-list >