Path: csiph.com!usenet.pasdenom.info!nntpfeed.proxad.net!proxad.net!feeder1-1.proxad.net!217.73.144.45.MISMATCH!feeder2.ecngs.de!ecngs!feeder.ecngs.de!border1.nntp.ams1.giganews.com!nntp.giganews.com!newsfeed.xs4all.nl!newsfeed8.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 0.057 X-Spam-Evidence: '*H*': 0.89; '*S*': 0.00; 'root': 0.04; 'cc:addr :python-list': 0.09; 'integer,': 0.09; 'url:blog': 0.10; '24,': 0.16; 'determining': 0.16; 'from:addr:rosuav': 0.16; 'from:name:chris angelico': 0.16; 'gregory': 0.16; 'wrote:': 0.16; "wouldn't": 0.16; '2015': 0.20; 'cc:2**0': 0.20; 'cc:addr:python.org': 0.20; 'header:In-Reply-To:1': 0.24; "doesn't": 0.26; 'fri,': 0.27; 'message-id:@mail.gmail.com': 0.27; 'mathematical': 0.27; 'aside': 0.32; 'possibly': 0.32; 'michael': 0.33; 'operations.': 0.33; 'definition': 0.34; 'received:google.com': 0.35; 'so,': 0.35; 'done': 0.35; 'something': 0.35; 'there': 0.36; 'pm,': 0.36; 'subject:: ': 0.37; 'being': 0.37; 'mean': 0.38; 'subject:with': 0.40; 'leading': 0.61; 'identify': 0.61; 'is.': 0.63; 'card': 0.63; 'talking': 0.67; 'jul': 0.72; 'treat': 0.72; 'square': 0.76; 'algorithm,': 0.84; 'chrisa': 0.84; 'subject:leading': 0.84; 'to:none': 0.91 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:cc :content-type; bh=Wo1uAf/4/DkD6bM7VH90pff4ngdaG0LV1ghh56RJj8s=; b=JgKpLw5VI52PbGzDhT3njP01K5s/aMUMGpdjwxd9nNjq5MhaIooa6txRb2QA6FQo2f E4FujmiXFPkGLNZrJ7AZrBawX8lTKL7LBlH1ApFqcWKrMWjuNwNsbilJlz/M6X/iFtNk Nft+GMnt72N9a7CFUT7/oNcaum3AOaEaZYRVR/OG8nvBognvRWCswjDfQfyYu/oZfZpO z2EuKAUF6dyHfu54uzoqWrvMi5wZZ9rQI48wAV3y+yEFakD0jWwxUvB+vqSMWGLXQ9s8 svE9mc2x4zIgXJ4hsMH8G5Sv19sEraNy14eKozBDhCJLDoFpuHKZcnxqs2qsOdbw7s53 suhQ== MIME-Version: 1.0 X-Received: by 10.50.136.194 with SMTP id qc2mr3975831igb.6.1437719327442; Thu, 23 Jul 2015 23:28:47 -0700 (PDT) In-Reply-To: References: <55ab37fb$0$1661$c3e8da3$5496439d@news.astraweb.com> <55aeea13$0$1669$c3e8da3$5496439d@news.astraweb.com> <55aefc70$0$1656$c3e8da3$5496439d@news.astraweb.com> <201507220712.t6M7CxJO014614@fido.openend.se> Date: Fri, 24 Jul 2015 16:28:47 +1000 Subject: Re: Integers with leading zeroes From: Chris Angelico Cc: "python-list@python.org" Content-Type: text/plain; charset=UTF-8 X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.20+ 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: 26 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1437719335 news.xs4all.nl 2861 [2001:888:2000:d::a6]:37447 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:94493 On Fri, Jul 24, 2015 at 4:23 PM, Gregory Ewing wrote: > Michael Torrie wrote: >> >> A credit card number is indeed a number, and there are >> mathematical formulas for determining if a particular number is a valid >> (as in well-formed) credit card number, > > > If you're talking about the check-digit algorithm, > that doesn't treat the whole number as an integer, > it works on the individual digits: > > http://www.datagenetics.com/blog/july42013/ > >> and possibly to identify what kind of card it is. > > > That's determined by the leading digits, and can > be done just as well by treating them as characters. So, the definition of a number is: Something on which you perform numeric operations. Aside from being circular, wouldn't this mean that "rope" is a number, since its square root is string? ChrisA