Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!feeder.erje.net!eu.feeder.erje.net!xlned.com!feeder7.xlned.com!news2.euro.net!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 0.049 X-Spam-Evidence: '*H*': 0.93; '*S*': 0.02; 'root': 0.05; 'noted,': 0.09; 'subject:number': 0.09; 'runs': 0.10; 'python': 0.11; 'from:addr:rosuav': 0.16; 'from:name:chris angelico': 0.16; 'subject:Prime': 0.16; 'subject:generator': 0.16; 'tweak': 0.16; 'wrote:': 0.18; 'thu,': 0.19; 'algorithms.': 0.24; 'header:In- Reply-To:1': 0.27; 'am,': 0.29; 'converting': 0.30; 'message- id:@mail.gmail.com': 0.30; 'received:google.com': 0.35; 'done': 0.36; 'to:addr:python-list': 0.38; 'rather': 0.38; 'to:addr:python.org': 0.39; 'ian': 0.60; 'jul': 0.74; 'prime': 0.74; 'square': 0.74; 'comparable': 0.84; 'excessive': 0.84; 'tossing': 0.84; '2013': 0.98 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=Ctcqki5T0NuAdFX77nZqq6nNWKLCpUcno1VV63rKFTo=; b=vxg6OGGhT1PdQZcv6q6Gsl8KGW+RZNv1jnlMNy3hIHqfXaglCbhQ2FXBk071p4uYUc /cXSoaWrQjaJUdSN6g7Ufx2usWD4xDpreJBPsLqvfCaIVHQhfznR1IxJZdP8dEDJ5IzC nfnC9mSHef5W3WbHBxPjBJmhDjURYDvislhro8J3N3QYeb4fGejsCu/Q6kmUaD/imABC EE2yb5Xh5WqZFwfDgDD48lBsHNyznB02Bs6oVd88TxOUopnvjfLEpNQ2WbaWz1W6laPE xSQ9kQketYuZE1+XnvzYzjughs1xXMt/tSKXWKZy/wUSeaCju6cmi9Tvf1NnIIeOIe+Y M5oQ== MIME-Version: 1.0 X-Received: by 10.221.4.4 with SMTP id oa4mr4826984vcb.70.1373476470740; Wed, 10 Jul 2013 10:14:30 -0700 (PDT) In-Reply-To: References: Date: Thu, 11 Jul 2013 03:14:30 +1000 Subject: Re: Prime number generator From: Chris Angelico To: python-list@python.org Content-Type: text/plain; charset=ISO-8859-1 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: 14 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1373476473 news.xs4all.nl 15994 [2001:888:2000:d::a6]:49212 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:50382 On Thu, Jul 11, 2013 at 2:54 AM, Ian Kelly wrote: > As promised. Apologies for the excessive commenting. As noted, this > implementation is a recursive generator, which is done so that the > primes in the sieve can go only up to the square root of the current > prime, rather than tossing in every prime seen so far. > Nice. Comes in at 0.23369310904039478 in my oh-so-scientific benchmarking, so it's comparable to several of Steven's algorithms. Runs on Python 3.3 with just the tiny tweak of converting iter.next() to next(iter). ChrisA