Path: csiph.com!usenet.pasdenom.info!gegeweb.org!de-l.enfer-du-nord.net!feeder2.enfer-du-nord.net!feeds.phibee-telecom.net!newsfeed.xs4all.nl!newsfeed2.news.xs4all.nl!xs4all!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 0.008 X-Spam-Evidence: '*H*': 0.98; '*S*': 0.00; 'python.': 0.02; 'python,': 0.02; 'output': 0.05; 'subject:PEP': 0.07; 'additionally': 0.09; 'literal': 0.09; 'pep': 0.09; 'used.': 0.09; 'python': 0.11; 'language.': 0.14; '10000000': 0.16; '7.98': 0.16; 'formatting.': 0.16; 'specifier': 0.16; 'str.format()': 0.16; 'appropriate': 0.16; 'language': 0.16; 'wed,': 0.18; 'code,': 0.22; '+0000': 0.22; 'issue.': 0.22; 'to:name:python-list@python.org': 0.22; 'integer': 0.24; 'received:65.55.116': 0.24; 'source': 0.25; 'skip:" 20': 0.27; 'header:In-Reply-To:1': 0.27; 'skip:- 40': 0.29; '[1]': 0.29; 'url:mailman': 0.30; 'code': 0.31; 'decimal': 0.31; 'fighting': 0.31; 'steven': 0.31; 'another': 0.32; 'url:python': 0.33; 'running': 0.33; 'call.': 0.33; 'raw': 0.33; 'date:': 0.34; 'maybe': 0.34; 'something': 0.35; 'but': 0.35; 'url:listinfo': 0.36; 'shows': 0.36; 'url:org': 0.36; 'so,': 0.37; 'email addr:python.org': 0.37; 'performance': 0.37; 'to:addr :python-list': 0.38; 'fact': 0.38; 'little': 0.38; 'subject:': 0.39; 'to:addr:python.org': 0.39; 'url:mail': 0.40; 'even': 0.60; 'above,': 0.60; 'full': 0.61; 'simple': 0.61; 'times': 0.62; 're:': 0.63; 'more': 0.64; 'different': 0.65; 'email name:python- list': 0.65; 'rendering': 0.68; '10%': 0.74; 'all!': 0.84; 'alternative.': 0.84; 'gain,': 0.84; 'fight': 0.97; '2013': 0.98 X-TMN: [v0rIGP/D3mQtlHL29IOTGelZAdPfgKME] X-Originating-Email: [carlosnepomuceno@outlook.com] From: Carlos Nepomuceno To: "python-list@python.org" Subject: RE: PEP 378: Format Specifier for Thousands Separator Date: Wed, 22 May 2013 06:38:45 +0300 Importance: Normal In-Reply-To: <519c36c6$0$6599$c3e8da3$5496439d@news.astraweb.com> References: , , , , , <519BD0D2.5080203@gmail.com>, , <519c30b0$0$6599$c3e8da3$5496439d@news.astraweb.com>, , <519c36c6$0$6599$c3e8da3$5496439d@news.astraweb.com> Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-OriginalArrivalTime: 22 May 2013 03:38:45.0471 (UTC) FILETIME=[DCCEAEF0:01CE569D] 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: 59 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1369193993 news.xs4all.nl 15964 [2001:888:2000:d::a6]:50707 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:45706 ----------------------------------------=0A= > From: steve+comp.lang.python@pearwood.info=0A= > Subject: Re: PEP 378: Format Specifier for Thousands Separator=0A= > Date: Wed=2C 22 May 2013 03:08:54 +0000=0A= > To: python-list@python.org=0A= [...]=0A= >> So=2C the only alternative to have "'%=2Cd' % x" rendering the thousands= =0A= >> separator output would a C source code modification?=0A= >=0A= > That's one alternative. But the language you would be then running will= =0A= > no longer be Python.=0A= >=0A= > Another alternative would be to write a pre-processor that parses your=0A= > Python source code=2C extracts any reference to the above=2C and replaces= it=0A= > with a call to the appropriate format call. But not only is that a lot of= =0A= > work for very little gain=2C but it's also more or less impossible to do = in=0A= > full generality. And again=2C what you are running will be something=0A= > different than Python=2C it will be Python plus a pre-processor.=0A= >=0A= >=0A= > Don't fight the language. You will lose.=0A= =0A= Not fighting the language. In fact it's not even a language issue.=0A= All I need is a standard library[1] improvement: "%=2Cd"! That's all!=0A= =0A= Just to put in perspective the performance difference of str.__mod__() and = str.format():=0A= =0A= C:\Python27>python -m timeit -cv -n10000000 "'%d'%12345"=0A= raw times: 0.386 0.38 0.373=0A= 10000000 loops=2C best of 3: 0.0373 usec per loop=0A= =0A= C:\Python27>python -m timeit -cv -n10000000 "'{:d}'.format(12345)"=0A= raw times: 7.91 7.89 7.98=0A= 10000000 loops=2C best of 3: 0.789 usec per loop=0A= =0A= C:\Python27>python -m timeit -cv -n10000000 "'{:=2Cd}'.format(12345)"=0A= raw times: 8.7 8.67 8.78=0A= 10000000 loops=2C best of 3: 0.867 usec per loop=0A= =0A= That shows str.format() is 20 times slower than str.__mod__() for a simple = decimal integer literal formatting.=0A= And it's additionally 10% slower if the thousands separator format specifie= r ('=2C') is used.=0A= =0A= [1] I think that translates to Python source code in 'Objects/stringobject.= c' and maybe 'Objects/unicodeobject.c'=0A= =0A= >=0A= >=0A= > --=0A= > Steven=0A= > --=0A= > http://mail.python.org/mailman/listinfo/python-list =