Path: csiph.com!usenet.pasdenom.info!weretis.net!feeder4.news.weretis.net!cs.uu.nl!news.stack.nl!newsfeed.xs4all.nl!newsfeed3.news.xs4all.nl!xs4all!newsgate.cistron.nl!newsgate.news.xs4all.nl!post.news.xs4all.nl!not-for-mail Return-Path: X-Original-To: python-list@python.org Delivered-To: python-list@mail.python.org X-Spam-Status: OK 0.001 X-Spam-Evidence: '*H*': 1.00; '*S*': 0.00; 'from:addr:yahoo.co.uk': 0.04; 'lawrence': 0.09; 'method,': 0.09; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'subject:method': 0.09; 'python': 0.11; 'bug': 0.12; 'language.': 0.14; "('b',": 0.16; "('r',": 0.16; '2),': 0.16; '2)]': 0.16; '5),': 0.16; "[('a',": 0.16; 'dict': 0.16; 'happily': 0.16; 'iterators,': 0.16; 'received:80.91.229.3': 0.16; 'received:plane.gmane.org': 0.16; 'sorted()': 0.16; 'underlying': 0.16; 'unneeded': 0.16; 'eager': 0.16; 'language': 0.16; 'wrote:': 0.18; "hasn't": 0.19; '>>>': 0.22; 'code,': 0.22; 'example': 0.22; 'header:User-Agent:1': 0.23; 'fine': 0.24; 'question': 0.24; 'suggested': 0.26; 'second': 0.26; 'header:X -Complaints-To:1': 0.27; 'header:In-Reply-To:1': 0.27; 'raise': 0.29; "i'm": 0.30; 'towards': 0.31; 'skip:c 30': 0.32; '(most': 0.33; 'sense': 0.34; "i'd": 0.34; 'could': 0.34; 'common': 0.35; '(2)': 0.35; 'but': 0.35; 'there': 0.35; 'really': 0.36; 'done,': 0.36; 'returning': 0.36; 'yield': 0.36; 'method': 0.36; "i'll": 0.36; 'should': 0.36; 'being': 0.38; 'implement': 0.38; 'to:addr :python-list': 0.38; 'list,': 0.38; 'structure': 0.39; 'to:addr:python.org': 0.39; 'enough': 0.39; 'received:org': 0.40; 'how': 0.40; 'most': 0.60; 'no.': 0.61; 'valuable': 0.63; 'our': 0.64; 'interest': 0.64; 'more': 0.64; 'news': 0.67; 'otten': 0.84; 'received:89': 0.85; 'lazy': 0.91; 'trend': 0.91; 'enhancement': 0.95 X-Injected-Via-Gmane: http://gmane.org/ To: python-list@python.org From: Mark Lawrence Subject: Re: collections Counter most_common method Date: Sun, 15 Dec 2013 16:36:07 +0000 References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Gmane-NNTP-Posting-Host: host-89-240-169-122.as13285.net User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 In-Reply-To: X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: General discussion list for the Python programming language List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Newsgroups: comp.lang.python Message-ID: Lines: 38 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1387125382 news.xs4all.nl 2930 [2001:888:2000:d::a6]:45472 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:61954 On 14/12/2013 19:42, Peter Otten wrote: > Mark Lawrence wrote: > >> This method returns a list, the example from The Fine Docs being:- >> >> >>> Counter('abracadabra').most_common(3) >> [('a', 5), ('r', 2), ('b', 2)] >> >> With the trend in Python being more and more towards methods returning >> iterators, is there ever likely to be an imost_common method, or has >> this been suggested and rejected, or what? I'm really just curious, but >> if enough people were to express an interest and it hasn't already been >> done, I'd happily raise an enhancement request on the bug tracker. > > As Counter is currently a dict you have to look at all items to find the > most common. With that underlying data structure I don't see how it could > make sense to yield the most common items incrementally. So > > (1) When would you prefer it over the the eager variant? > (2) How would you implement it? > > By the way, if you can come up with a plausible answer for the second > question you should aim higher, for lazy heapq.nlargest() and sorted() > functions... > Coming from my No. 1 MVP (Most Valuable Pythonista) I'll take that as an emphatic no :) The good news from my POV is that while thinking about this, then looking at my code, I completely eliminated an unneeded data structure. -- My fellow Pythonistas, ask not what our language can do for you, ask what you can do for our language. Mark Lawrence