Path: csiph.com!usenet.pasdenom.info!weretis.net!feeder4.news.weretis.net!rt.uk.eu.org!newsfeed.xs4all.nl!newsfeed2a.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; 'resulting': 0.04; 'memory.': 0.07; 'string': 0.09; 'arrays': 0.09; 'bytes.': 0.09; 'strings.': 0.09; 'subject:keys': 0.09; 'cc:addr:python-list': 0.11; '23,': 0.16; 'adam': 0.16; 'from:addr:rosuav': 0.16; 'from:name:chris angelico': 0.16; 'functions;': 0.16; 'hashes': 0.16; 'integer.': 0.16; "languages'": 0.16; 'sorts': 0.16; 'subject:sqlite3': 0.16; 'followed': 0.16; 'language': 0.16; 'wrote:': 0.18; 'things.': 0.19; 'cc:addr:python.org': 0.22; 'byte': 0.24; 'bytes': 0.24; 'interpret': 0.24; 'module,': 0.24; 'string,': 0.24; 'cc:2**0': 0.24; 'least': 0.26; 'header:In-Reply- To:1': 0.27; 'am,': 0.29; 'characters': 0.30; 'message- id:@mail.gmail.com': 0.30; 'along': 0.30; 'usually': 0.31; 'struct': 0.31; 'probably': 0.32; 'fri,': 0.33; 'maybe': 0.34; 'but': 0.35; 'received:google.com': 0.35; 'there': 0.35; 'really': 0.36; 'sequence': 0.36; 'done': 0.36; 'how': 0.40; 'easy': 0.60; 'number,': 0.60; 'designers': 0.74; 'you;': 0.84; 'to:none': 0.92 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=vQIPsEVDSgtierRTZPjWZdhy9K9SzoDx2RSzt25dBYI=; b=FG/J09y/4J5LFNNP2FWdUu5kaLXefoVszoBHVWAEU2Zs7xbb/K/d1l8pRVHIsnETIS qrzuPlq/Uwi9rllxgBnfm0b2e5xo5kdMQaFqw0Hsr4b2nyYnx1XlY8F5hCjBA4rJH4MT VOFsHe17JgWRoRQNHhUU+JoEvUzx1AvXkBUAaQ5YvOqyVzLX2k5I7K/+zpPmPEmFkHoB f3k2r87v9ywP0FPPgNbnRbYeyMG2r0Z8e4BfexLZnVDSdT51z5RETzluJ/pdM3Sy6gWj Qpo1rn8QS6DI8PSiwjuNedt4qvwCUTU80NnBZc4VDfMfMJdT3s4+jbAaEuf4OjQshalr tZhQ== MIME-Version: 1.0 X-Received: by 10.220.133.197 with SMTP id g5mr16403650vct.20.1400771370654; Thu, 22 May 2014 08:09:30 -0700 (PDT) In-Reply-To: References: <05c15bxrpj.ln2@news.ducksburg.com> Date: Fri, 23 May 2014 01:09:30 +1000 Subject: Re: hashing strings to integers for sqlite3 keys From: Chris Angelico Cc: "python-list@python.org" Content-Type: text/plain; charset=UTF-8 X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.15 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: 22 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1400771378 news.xs4all.nl 2961 [2001:888:2000:d::a6]:46563 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:71898 On Fri, May 23, 2014 at 12:47 AM, Adam Funk wrote: >> I don't know that there is, at least not with hashlib. You might be >> able to use digest() followed by the struct module, but it's no less >> convoluted. It's the same in several other languages' hashing >> functions; the result is a string, not an integer. > > Well, J*v* returns a byte array... I counted byte arrays along with strings. Whether it's notionally a string of bytes or characters makes no difference - it's not an integer. > I dunno why language designers don't make it easy to get a single big > number directly out of these things. It's probably because these sorts of hashes are usually done on large puddles of memory, to create a smaller puddle of memory. How you interpret the resulting puddle is up to you; maybe you want to think of it as a number, maybe as a string, but really it's just a sequence of bytes. ChrisA