Path: csiph.com!fu-berlin.de!uni-berlin.de!not-for-mail From: Michael Selik Newsgroups: comp.lang.python Subject: Re: Drowning in a teacup? Date: Sat, 02 Apr 2016 05:51:46 +0000 Lines: 30 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-Trace: news.uni-berlin.de sIizKUdtFzOxg/0scUqgVg8bzm3SziT0VP92P1D+M23A== Return-Path: X-Original-To: python-list@python.org Delivered-To: python-list@mail.python.org X-Spam-Status: OK 0.004 X-Spam-Evidence: '*H*': 0.99; '*S*': 0.00; 'matches': 0.07; 'strings.': 0.07; 'suggestions.': 0.09; '>>>': 0.15; 'key?': 0.16; 'keyword,': 0.16; 'list)': 0.16; 'received:io': 0.16; 'received:psf.io': 0.16; 'wrote:': 0.16; 'element': 0.18; '>': 0.18; '(in': 0.18; 'email addr:gmail.com>': 0.18; '>>>': 0.20; 'to:2**1': 0.21; 'elements': 0.23; 'sat,': 0.23; 'header:In-Reply-To:1': 0.24; 'sort': 0.25; 'message- id:@mail.gmail.com': 0.27; 'function': 0.28; '(new': 0.29; 'relative': 0.30; "i'd": 0.31; 'post': 0.31; "can't": 0.32; 'list': 0.34; 'received:google.com': 0.35; 'something': 0.35; 'list,': 0.36; 'received:209.85': 0.36; 'beginning': 0.36; 'to:addr:python-list': 0.36; 'subject:?': 0.36; 'subject:: ': 0.37; 'expect': 0.37; 'list.': 0.37; 'front': 0.38; 'received:209': 0.38; 'skip:e 20': 0.39; 'to:addr:python.org': 0.40; 'snap': 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=xAzsMyGKD1qTTxMbs3Un0bB/EvPDwtWjOlbiiuyMd1g=; b=Df/aUHUYnlV2fZXj9eAZSSxROcfrJ04LEmYAbzS3JObx/MJ0C0wXhUmKx5UfrwuAAM VgXSijGcmK2Og4dmumAajcVMQQR8grKmna/Q33r87tNTMclNgpvNeDzXfG32iKBTmD4X nyyNnHtFwvx6ahx6MfVJFFpQSPJjKsptMkMJAXbu5kNXHiOge5wOr2cdbGIFFKDf8phe YuAKHbGNYSI9lbLpfWywWdYofbYlrDw288VLOeuVM+VHVJLENqjaolrtbnkSkwUwM/W7 gADCJj9VJhJUcE5gYHp67DHfSZOGDIqOHIfbkODk+zANLL/qrDK4VkZuDwxB5sgwzkZT HhbA== 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=xAzsMyGKD1qTTxMbs3Un0bB/EvPDwtWjOlbiiuyMd1g=; b=UObdpELdcXV2QtE2Gb7vZHc7POnawWpalHNA5LaOECaDI0tFUqZwig44VTlw0dZHMh 5tr36JA5JFjLUnS6WnUR8lqFx34OwsQpQeBFQDRDI+t7nBv3pU9Q5KplKiGj/X64PCJm lgvE4W6dwnuAsmP/+5+AGe3ukPdQWszieHoTpK1ucYPyoI2VMy4/3G2KMjWMoQsJ7rGv lfBu5FijHM/RpS6AMsOyM/kYuFV6WyEzsfeJrGlWonDr391OVaxwOyizCy/T9e5sactN s3u2zTrFQpOHz9Be6V4XxDhLROMYKIsdQlsHX45AhooXouT2yqgsOTbQa3G/8l4CO53s Dhrg== X-Gm-Message-State: AD7BkJKh3XNOVW77W2JPx3tFo+HNycOlTiAgsc1RoKr9ixYcjX8e0xSnkmZoMrlHKGtaIf0lWTle/RoNiAPyKA== X-Received: by 10.140.22.212 with SMTP id 78mr29425558qgn.77.1459576315326; Fri, 01 Apr 2016 22:51:55 -0700 (PDT) In-Reply-To: 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:106276 On Sat, Apr 2, 2016, 1:46 AM Vito De Tullio wrote: > Fillmore wrote: > > > I need to scan a list of strings. If one of the elements matches the > > beginning of a search keyword, that element needs to snap to the front > > of the list. > > I know this post regards the function passing, but, on you specific > problem, > can't you just ... sort the list with a custom key? > > something like (new list) > > >>> sorted(['no_a', 'yes_c', 'no_b', 'yes_z', 'no_y', 'yes_x'], > ... key=lambda e: not e.startswith('yes')) > ['yes_c', 'yes_z', 'yes_x', 'no_a', 'no_b', 'no_y'] > > or (in place) > > >>> l = ['no_a', 'yes_c', 'no_b', 'yes_z', 'no_y', 'yes_x'] > >>> l.sort(key=lambda e: not e.startswith('yes')) > >>> l > ['yes_c', 'yes_z', 'yes_x', 'no_a', 'no_b', 'no_y'] > If the number of matches is small relative to the size of the list, I'd expect the sort would be slower than most of the other suggestions. >