Re: bit count or bit set && Python3

Path	csiph.com!usenet.pasdenom.info!goblin2!goblin.stu.neva.ru!newsfeed.xs4all.nl!newsfeed5.news.xs4all.nl!xs4all!post.news.xs4all.nl!not-for-mail
Return-Path	<python-python-list@m.gmane.org>
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; 'python3': 0.05; 'test,': 0.05; 'bits': 0.07; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'subject:Python3': 0.09; 'subject:set': 0.09; 'decent': 0.16; 'equivalents': 0.16; 'integers,': 0.16; 'operation.': 0.16; 'pypi.': 0.16; 'received:80.91.229.3': 0.16; 'received:plane.gmane.org': 0.16; 'subject:bit': 0.16; 'wrote:': 0.17; 'integer': 0.17; 'tests': 0.18; 'bit': 0.21; 'logical': 0.22; "i'd": 0.22; 'header:In-Reply-To:1': 0.25; 'header:User- Agent:1': 0.26; 'operations,': 0.27; 'correct': 0.28; 'header:X -Complaints-To:1': 0.28; 'this?': 0.28; 'probably': 0.29; "i'm": 0.29; 'implement': 0.32; 'from:addr:yahoo.co.uk': 0.32; 'to:addr :python-list': 0.33; 'needed': 0.35; 'there': 0.35; 'received:org': 0.36; 'but': 0.36; "i'll": 0.36; 'drop': 0.37; 'subject:: ': 0.38; 'mark': 0.38; 'to:addr:python.org': 0.39; 'header:Received:5': 0.40; 'union': 0.66; 'light-weight': 0.84
X-Injected-Via-Gmane	http://gmane.org/
To	python-list@python.org
From	Mark Lawrence <breamoreboy@yahoo.co.uk>
Subject	Re: bit count or bit set && Python3
Date	Thu, 25 Oct 2012 17:24:29 +0100
References	<5089511E.4090009@earthlink.net>
Mime-Version	1.0
Content-Type	text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding	7bit
X-Gmane-NNTP-Posting-Host	host-78-147-17-218.as13285.net
User-Agent	Mozilla/5.0 (Windows NT 6.0; rv:16.0) Gecko/20121010 Thunderbird/16.0.1
In-Reply-To	<5089511E.4090009@earthlink.net>
X-Antivirus	avast! (VPS 121025-1, 25/10/2012), Outbound message
X-Antivirus-Status	Clean
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	<http://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	<http://mail.python.org/mailman/listinfo/python-list>, <mailto:python-list-request@python.org?subject=subscribe>
Newsgroups	comp.lang.python
Message-ID	<mailman.2851.1351182149.27098.python-list@python.org> (permalink)
Lines	22
NNTP-Posting-Host	2001:888:2000:d::a6
X-Trace	1351182149 news.xs4all.nl 6852 [2001:888:2000:d::a6]:40841
X-Complaints-To	abuse@xs4all.nl
Xref	csiph.com comp.lang.python:32142

Show key headers only | View raw

On 25/10/2012 15:47, Charles Hixson wrote:
> In Python3 is there any good way to count the number of on bits in an
> integer (after an & operation)?
> Alternatively, is there any VERY light-weight implementation of a bit
> set?  I'd prefer to use integers, as I'm probably going to need
> thousands of these, if the tests work out.  But before I can test, I
> need a decent bit counter.  (shift, xor, &, and | are already present
> for integer values, but I also need to count the number of "true" items
> after the logical operation.  So if a bitset is the correct approach,
> I'll need it to implement those operations, or their equivalents in
> terms of union and intersection.)
>
> Or do I need to drop into C for this?
>

If needed bitarray and bitstring are available on pypi.

-- 
Cheers.

Mark Lawrence.

Back to comp.lang.python | Previous | Next | Find similar | Unroll thread

Thread

Re: bit count or bit set && Python3 Mark Lawrence <breamoreboy@yahoo.co.uk> - 2012-10-25 17:24 +0100

csiph-web