Account Options

  1. Sign in
The old Google Groups will be going away soon, but your browser is incompatible with the new version.
Google Groups Home
« Groups Home
Message from discussion bit count or bit set && Python3

Received: by 10.68.241.99 with SMTP id wh3mr137459pbc.1.1351477546754;
        Sun, 28 Oct 2012 19:25:46 -0700 (PDT)
Path: s9ni66461pbb.0!nntp.google.com!border1.nntp.dca.giganews.com!border4.nntp.dca.giganews.com!border2.nntp.dca.giganews.com!novia!news-peer1!btnet!zen.net.uk!hamilton.zen.co.uk!xlned.com!feeder1.xlned.com!border2.nntp.ams.giganews.com!nntp.giganews.com!newsreader4.netcologne.de!news.netcologne.de!feeds.phibee-telecom.net!newsfeed.xs4all.nl!newsfeed6.news.xs4all.nl!xs4all!post.news.xs4all.nl!not-for-mail
Return-Path: <charleshi...@earthlink.net>
X-Original-To: python-l...@python.org
Delivered-To: python-l...@mail.python.org
X-Spam-Status: OK 0.001
X-Spam-Evidence: '*H*': 1.00; '*S*': 0.00; 'python3': 0.05; 'test,':
	0.05; 'bits': 0.07; 'subject:Python3': 0.09; 'subject:set': 0.09;
	'decent': 0.16; 'equivalents': 0.16; 'integers,': 0.16; 'message-
	id:@earthlink.net': 0.16; 'operation.': 0.16;
	'received:dsl.mindspring.com': 0.16; 'subject:bit': 0.16;
	'integer': 0.17; 'tests': 0.18; 'bit': 0.21; 'logical': 0.22;
	"i'd": 0.22; 'header:User-Agent:1': 0.26; 'operations,': 0.27;
	'correct': 0.28; 'this?': 0.28; 'probably': 0.29; "i'm": 0.29;
	'implement': 0.32; 'to:addr:python-list': 0.33; 'there': 0.35;
	'but': 0.36; "i'll": 0.36; 'drop': 0.37; 'to:addr:python.org':
	0.39; 'union': 0.66; 'light-weight': 0.84
Date: Wed, 24 Oct 2012 19:19:55 -0700
From: Charles Hixson <charleshi...@earthlink.net>
User-Agent: Mozilla/5.0 (X11; Linux x86_64;
	rv:10.0.7) Gecko/20120922 Icedove/10.0.7
MIME-Version: 1.0
To: python-l...@python.org
Subject: bit count or bit set && Python3
X-BeenThere: python-l...@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-requ...@python.org?subject=unsubscribe>
List-Archive: <http://mail.python.org/pipermail/python-list/>
List-Post: <mailto:python-l...@python.org>
List-Help: <mailto:python-list-requ...@python.org?subject=help>
List-Subscribe: <http://mail.python.org/mailman/listinfo/python-list>,
	<mailto:python-list-requ...@python.org?subject=subscribe>
Newsgroups: comp.lang.python
Message-ID: <mailman.2869.1351200329.27098.python-l...@python.org>
Lines: 16
NNTP-Posting-Host: 2001:888:2000:d::a6
X-Trace: 1351200329 news.xs4all.nl 6913 [2001:888:2000:d::a6]:58793
X-Complaints-To: ab...@xs4all.nl
Bytes: 3099
X-Original-Bytes: 3032
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit

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?

-- 
Charles Hixson