Path: csiph.com!usenet.pasdenom.info!weretis.net!feeder4.news.weretis.net!feeder2.ecngs.de!ecngs!feeder.ecngs.de!xlned.com!feeder1.xlned.com!newsfeed.xs4all.nl!newsfeed5.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 0.000 X-Spam-Evidence: '*H*': 1.00; '*S*': 0.00; 'binary': 0.05; '"c"': 0.07; 'builtin': 0.07; 'subject:How': 0.09; 'python': 0.09; '"a"': 0.09; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'def': 0.10; 'aug': 0.13; '"-"': 0.16; '"0"': 0.16; '"2"': 0.16; '"b"': 0.16; '"d"': 0.16; '"f"': 0.16; "'0'": 0.16; 'hex': 0.16; 'received:80.91.229.3': 0.16; 'received:plane.gmane.org': 0.16; 'valueerror,': 0.16; 'mon,': 0.16; 'string': 0.17; 'integer': 0.17; '>>>': 0.18; '(not': 0.20; 'import': 0.21; 'raise': 0.24; 'skip:" 20': 0.26; '2.6': 0.27; 'header:X-Complaints-To:1': 0.28; 'function': 0.30; '+0200,': 0.33; 'url:home': 0.33; 'to:addr :python-list': 0.33; 'typically': 0.33; "can't": 0.34; 'done': 0.34; 'subject:?': 0.35; 'received:org': 0.36; 'but': 0.36; 'charset:us-ascii': 0.36; 'subject:: ': 0.38; 'positive': 0.38; 'to:addr:python.org': 0.39; 'header:Received:5': 0.40; 'think': 0.40; 'dennis': 0.91; 'received:108': 0.91 X-Injected-Via-Gmane: http://gmane.org/ To: python-list@python.org From: Dennis Lee Bieber Subject: Re: How to convert base 10 to base 2? Date: Mon, 20 Aug 2012 13:29:56 -0400 Organization: > Bestiaria Support Staff < References: <1cedbf80-117b-48aa-a9f2-754293203408@googlegroups.com> <28b3f583-fad1-46da-a6b5-933f966eb401@googlegroups.com> <50324F3A.7040001@sequans.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Gmane-NNTP-Posting-Host: 108.79.223.235 X-Newsreader: Forte Agent 3.3/32.846 X-No-Archive: YES X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.12 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: 52 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1345483790 news.xs4all.nl 6924 [2001:888:2000:d::a6]:55901 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:27513 On Mon, 20 Aug 2012 16:52:42 +0200, Jean-Michel Pichavant declaimed the following in gmane.comp.python.general: > note that the builtin bin function is not available with python ver < 2.6 > > def Denary2Binary(n): > '''convert denary integer n to binary string bStr''' > bStr = '' > if n < 0: raise ValueError, "must be a positive integer" > if n == 0: return '0' > while n > 0: > bStr = str(n % 2) + bStr > n = n >> 1 > return bStr > > JM > > (not my function but I can't remember who I stole from) I think I typically have done this by going through a hex representation. H2B_Lookup = { "0" : "0000", "1" : "0001", "2" : "0010", "3" : "0011", "4" : "0100", "5" : "0101", "6" : "0110", "7" : "0111", "8" : "1000", "9" : "1001", "A" : "1010", "B" : "1011", "C" : "1100", "D" : "1101", "D" : "1110", "F" : "1111" } def I2B(i): sgn = " " if i < 0: sgn = "-" i = -i h = ("%X" % i) return sgn + "".join([H2B_Lookup[c] for c in h]) >>> from i2b import I2B >>> I2B(10) ' 1010' >>> I2B(1238) ' 010011100110' >>> I2B(-6) '-0110' >>> -- Wulfraed Dennis Lee Bieber AF6VN wlfraed@ix.netcom.com HTTP://wlfraed.home.netcom.com/