Re: hashing strings to integers for sqlite3 keys

Path	csiph.com!usenet.pasdenom.info!aioe.org!news.stack.nl!newsfeed.xs4all.nl!newsfeed2.news.xs4all.nl!xs4all!post.news.xs4all.nl!not-for-mail
Return-Path	<rosuav@gmail.com>
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; '(using': 0.07; 'lately': 0.07; 'string': 0.09; '22,': 0.09; 'subject:keys': 0.09; 'cc:addr :python-list': 0.11; '"hello': 0.16; '16)': 0.16; 'adam': 0.16; 'from:addr:rosuav': 0.16; 'from:name:chris angelico': 0.16; 'functions;': 0.16; 'hashlib': 0.16; 'hex': 0.16; 'integer.': 0.16; 'internally': 0.16; "languages'": 0.16; 'sha1': 0.16; 'subject:sqlite3': 0.16; 'ties': 0.16; 'followed': 0.16; 'wrote:': 0.18; 'thu,': 0.19; '>>>': 0.22; 'import': 0.22; 'cc:addr:python.org': 0.22; 'module,': 0.24; 'string,': 0.24; "haven't": 0.24; 'looks': 0.24; '---': 0.24; 'question': 0.24; 'cc:2**0': 0.24; "i've": 0.25; 'least': 0.26; 'header:In-Reply- To:1': 0.27; 'wondering': 0.29; 'related': 0.29; 'converting': 0.30; 'message-id:@mail.gmail.com': 0.30; '(which': 0.31; 'getting': 0.31; "skip:' 40": 0.31; 'struct': 0.31; 'but': 0.35; 'received:google.com': 0.35; 'there': 0.35; 'pm,': 0.38; 'rather': 0.38; 'inefficient': 0.91; '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=/7DL406NA4LHYBRRg3PQflr/sFIFkt/9z8ihPHNSlVo=; b=dkMZ6PfNGRKoOVh7oZXzQYyU2dHSNYujUnPZC9qVF2ORX3lAtHb+l7zErubs+6LFhZ 7QRKUJzOQigVzKLqhEL5ua40YSfESbvngr4QjcLRbUi3bAlNdeYJ3UA83kkNqP8A2YKh l2QWyLkTSM5+U5oiwSK/S2OROmFdIWZ/D3SIobx00w27fHWPPsfbUK9SiJ+1dvYDnw7S pLAqQ7COeDAzI57Ed6v1epPJJwHgMw+wQfGeGOwVTWxPrCdCeGU8fM1Cl5OYef/Fdrv1 Cm0Yv9oUNY+sVkGTu9yMUTBhRVBIIbGLzO/Oj8/k7HI6eqYrMGTTUzb04XbZgyx41AkO pwSA==
MIME-Version	1.0
X-Received	by 10.58.160.134 with SMTP id xk6mr671392veb.64.1400768050574; Thu, 22 May 2014 07:14:10 -0700 (PDT)
In-Reply-To	<05c15bxrpj.ln2@news.ducksburg.com>
References	<jn415bx6uf.ln2@news.ducksburg.com> <mailman.10220.1400764235.18130.python-list@python.org> <05c15bxrpj.ln2@news.ducksburg.com>
Date	Fri, 23 May 2014 00:14:10 +1000
Subject	Re: hashing strings to integers for sqlite3 keys
From	Chris Angelico <rosuav@gmail.com>
Cc	"python-list@python.org" <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 <python-list.python.org>
List-Unsubscribe	<https://mail.python.org/mailman/options/python-list>, <mailto:python-list-request@python.org?subject=unsubscribe>
List-Archive	<http://mail.python.org/pipermail/python-list/>
List-Post	<mailto:python-list@python.org>
List-Help	<mailto:python-list-request@python.org?subject=help>
List-Subscribe	<https://mail.python.org/mailman/listinfo/python-list>, <mailto:python-list-request@python.org?subject=subscribe>
Newsgroups	comp.lang.python
Message-ID	<mailman.10223.1400768058.18130.python-list@python.org> (permalink)
Lines	22
NNTP-Posting-Host	2001:888:2000:d::a6
X-Trace	1400768058 news.xs4all.nl 2861 [2001:888:2000:d::a6]:52353
X-Complaints-To	abuse@xs4all.nl
Xref	csiph.com comp.lang.python:71893

Show key headers only | View raw

On Thu, May 22, 2014 at 11:54 PM, Adam Funk <a24061@ducksburg.com> wrote:
>>  >>> from hashlib import sha1
>>  >>> s = "Hello world"
>>  >>> h = sha1(s)
>>  >>> h.hexdigest()
>>   '7b502c3a1f48c8609ae212cdfb639dee39673f5e'
>>  >>> int(h.hexdigest(), 16)
>>   703993777145756967576188115661016000849227759454L
>
> That ties in with a related question I've been wondering about lately
> (using MD5s & SHAs for other things) --- getting a hash value (which
> is internally numeric, rather than string, right?) out as a hex string
> & then converting that to an int looks inefficient to me --- is there
> any better way to get an int?  (I haven't seen any other way in the
> API.)

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.

ChrisA

Thread

hashing strings to integers for sqlite3 keys Adam Funk <a24061@ducksburg.com> - 2014-05-22 12:47 +0100
  Re: hashing strings to integers for sqlite3 keys Peter Otten <__peter__@web.de> - 2014-05-22 14:58 +0200
    Re: hashing strings to integers for sqlite3 keys Adam Funk <a24061@ducksburg.com> - 2014-05-22 14:41 +0100
      Re: hashing strings to integers for sqlite3 keys Chris Angelico <rosuav@gmail.com> - 2014-05-23 00:08 +1000
        Re: hashing strings to integers for sqlite3 keys Adam Funk <a24061@ducksburg.com> - 2014-05-22 15:40 +0100
  Re: hashing strings to integers for sqlite3 keys Chris Angelico <rosuav@gmail.com> - 2014-05-22 23:03 +1000
    Re: hashing strings to integers for sqlite3 keys Adam Funk <a24061@ducksburg.com> - 2014-05-22 14:47 +0100
  Re: hashing strings to integers for sqlite3 keys Tim Chase <python.list@tim.thechases.com> - 2014-05-22 08:09 -0500
    Re: hashing strings to integers for sqlite3 keys Adam Funk <a24061@ducksburg.com> - 2014-05-22 14:54 +0100
      Re: hashing strings to integers for sqlite3 keys Chris Angelico <rosuav@gmail.com> - 2014-05-23 00:14 +1000
        Re: hashing strings to integers for sqlite3 keys Adam Funk <a24061@ducksburg.com> - 2014-05-22 15:47 +0100
          Re: hashing strings to integers for sqlite3 keys Chris Angelico <rosuav@gmail.com> - 2014-05-23 01:09 +1000
          Re: hashing strings to integers for sqlite3 keys Peter Otten <__peter__@web.de> - 2014-05-22 17:34 +0200
            hashing strings to integers (was: hashing strings to integers for sqlite3 keys) Adam Funk <a24061@ducksburg.com> - 2014-05-23 11:27 +0100
              Re: hashing strings to integers Adam Funk <a24061@ducksburg.com> - 2014-05-23 11:36 +0100
                Re: hashing strings to integers Chris Angelico <rosuav@gmail.com> - 2014-05-23 21:01 +1000
              Re: hashing strings to integers (was: hashing strings to integers for sqlite3 keys) Chris Angelico <rosuav@gmail.com> - 2014-05-23 20:59 +1000
                Re: hashing strings to integers Adam Funk <a24061@ducksburg.com> - 2014-05-27 16:13 +0100
                Re: hashing strings to integers Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2014-05-27 17:02 +0000
                Re: hashing strings to integers Chris Angelico <rosuav@gmail.com> - 2014-05-28 05:16 +1000
                Re: hashing strings to integers Dan Sommers <dan@tombstonezero.net> - 2014-05-28 01:55 +0000
                Re: hashing strings to integers Adam Funk <a24061@ducksburg.com> - 2014-06-03 11:29 +0100
                Re: hashing strings to integers Adam Funk <a24061@ducksburg.com> - 2014-06-03 11:32 +0100
              Re: hashing strings to integers Terry Reedy <tjreedy@udel.edu> - 2014-05-23 15:10 -0400
                Re: hashing strings to integers Adam Funk <a24061@ducksburg.com> - 2014-05-27 16:20 +0100
  Re: hashing strings to integers for sqlite3 keys alister <alister.nospam.ware@ntlworld.com> - 2014-05-22 14:48 +0000

csiph-web