Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > comp.lang.python > #60961

Re: extracting a heapq in a for loop - there must be more elegant solution

Path csiph.com!usenet.pasdenom.info!weretis.net!feeder4.news.weretis.net!rt.uk.eu.org!newsfeed.xs4all.nl!newsfeed1.news.xs4all.nl!xs4all!post.news.xs4all.nl!not-for-mail
Return-Path <cameron@cskk.homeip.net>
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; 'example:': 0.03; 'essentially': 0.04; 'extracted': 0.09; 'iterate': 0.09; 'storage.': 0.09; 'wrapper': 0.09; 'python': 0.11; 'factory': 0.16; 'from:addr:cs': 0.16; 'from:addr:zip.com.au': 0.16; 'from:name:cameron simpson': 0.16; 'heapq': 0.16; 'henry': 0.16; 'iterable,': 0.16; 'loop.': 0.16; 'message-id:@cskk.homeip.net': 0.16; 'received:211.29': 0.16; 'received:211.29.132': 0.16; 'received:cskk.homeip.net': 0.16; 'received:homeip.net': 0.16; 'received:optusnet.com.au': 0.16; 'received:syd.optusnet.com.au': 0.16; 'reinvent': 0.16; 'simpson': 0.16; 'subject: \n ': 0.16; 'url:cskk': 0.16; 'url:ezoshosting': 0.16; 'elements': 0.16; 'wrote:': 0.18; 'module': 0.19; 'example': 0.22; 'import': 0.22; 'header:User-Agent:1': 0.23; 'cheers,': 0.24; 'header:In-Reply- To:1': 0.27; 'unix': 0.29; 'class': 0.32; 'stuff': 0.32; 'regular': 0.32; "i'd": 0.34; "can't": 0.35; 'received:com.au': 0.36; 'charset:us-ascii': 0.36; 'too': 0.37; 'received:211': 0.38; 'skip:[ 10': 0.38; 'to:addr:python-list': 0.38; '(from': 0.39; 'to:addr:python.org': 0.39; 'called': 0.40; 'how': 0.40; 'subject: ': 0.61; 'mentioned': 0.61; 'content-disposition:inline': 0.62; 'personal': 0.63; 'subject:more': 0.64; 'more': 0.64; 'believe': 0.68; 'nobody': 0.68; 'subject:there': 0.68; 'toronto': 0.91
Date Wed, 4 Dec 2013 08:13:03 +1100
From Cameron Simpson <cs@zip.com.au>
To python-list@python.org
Subject Re: extracting a heapq in a for loop - there must be more elegant solution
MIME-Version 1.0
Content-Type text/plain; charset=us-ascii
Content-Disposition inline
In-Reply-To <bg60hjF83eoU1@mid.dfncis.de>
User-Agent Mutt/1.5.21 (2010-09-15)
References <bg60hjF83eoU1@mid.dfncis.de>
X-Optus-CM-Score 0
X-Optus-CM-Analysis v=2.1 cv=YYGEuWhf c=1 sm=1 tr=0 a=YuQlxtEQCowy2cfE5kc7TA==:117 a=YuQlxtEQCowy2cfE5kc7TA==:17 a=ZtCCktOnAAAA:8 a=PO7r1zJSAAAA:8 a=LcaDllckn3IA:10 a=jRJTwREybbQA:10 a=kj9zAlcOel0A:10 a=vrnE16BAAAAA:8 a=8AHkEIZyAAAA:8 a=sJoo9Cljmp4A:10 a=lyG38BaPAAAA:8 a=4Jym8Q_jdICGQ6ZnDEQA:9 a=CjuIK1q_8ugA:10
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.3528.1386105197.18130.python-list@python.org> (permalink)
Lines 43
NNTP-Posting-Host 2001:888:2000:d::a6
X-Trace 1386105197 news.xs4all.nl 2877 [2001:888:2000:d::a6]:55302
X-Complaints-To abuse@xs4all.nl
Xref csiph.com comp.lang.python:60961

Show key headers only | View raw


On 03Dec2013 12:18, Helmut Jarausch <jarausch@igpm.rwth-aachen.de> wrote:
> I'd like to extracted elements from a heapq in a for loop.
> I feel my solution below is much too complicated.
> How to do it more elegantly? 

I can't believe nobody has mentioned PriorityQueue.

A PriorityQueue (from the queue module in python 3 and the Queue
module in python 2) is essentially just a regular Queue using a
heapq for the storage.

Example (untested):

  from Queue import PriorityQueue

  PQ = PriorityQueue()
  for item in [1,2,3,7,6,5,9,4]:
    PQ.put(item)

  while not PQ.empty():
    item = PQ.get()
    ... do stuff with item ...

I iterate over Queues so often that I have a personal class called
a QueueIterator which is a wrapper for a Queue or PriorityQueue
which is iterable, and an IterablePriorityQueue factory function.
Example:

  from cs.queues import IterablePriorityQueue

  IPQ = IterablePriorityQueue()
  for item in [1,2,3,7,6,5,9,4]:
    IPQ.put(item)

  for item in IPQ:
    ... do stuff with item ...

Cheers,
-- 
Cameron Simpson <cs@zip.com.au> http://www.cskk.ezoshosting.com/cs/

Those who do not understand Unix are condemned to reinvent it, poorly.
        - Henry Spencer @ U of Toronto Zoology, henry@zoo.toronto.edu

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


Thread

extracting a heapq in a for loop - there must be  more elegant solution Helmut Jarausch <jarausch@igpm.rwth-aachen.de> - 2013-12-03 12:18 +0000
  Re: extracting a heapq in a for loop - there must be more elegant solution Peter Otten <__peter__@web.de> - 2013-12-03 13:38 +0100
    Re: extracting a heapq in a for loop - there must be more elegant solution Helmut Jarausch <jarausch@igpm.rwth-aachen.de> - 2013-12-04 09:36 +0000
      Re: extracting a heapq in a for loop - there must be more elegant solution Peter Otten <__peter__@web.de> - 2013-12-04 10:50 +0100
  Re: extracting a heapq in a for loop - there must be  more elegant solution rusi <rustompmody@gmail.com> - 2013-12-03 04:40 -0800
    Re: extracting a heapq in a for loop - there must be  more elegant solution Helmut Jarausch <jarausch@igpm.rwth-aachen.de> - 2013-12-04 09:37 +0000
  Re: extracting a heapq in a for loop - there must be  more elegant solution Duncan Booth <duncan.booth@invalid.invalid> - 2013-12-03 13:06 +0000
    Re: extracting a heapq in a for loop - there must be  more elegant solution Helmut Jarausch <jarausch@igpm.rwth-aachen.de> - 2013-12-04 09:39 +0000
  Re: extracting a heapq in a for loop - there must be  more elegant solution Jussi Piitulainen <jpiitula@ling.helsinki.fi> - 2013-12-03 15:56 +0200
    Re: extracting a heapq in a for loop - there must be  more elegant solution Helmut Jarausch <jarausch@igpm.rwth-aachen.de> - 2013-12-04 09:41 +0000
  Re: extracting a heapq in a for loop - there must be  more elegant solution Cameron Simpson <cs@zip.com.au> - 2013-12-04 08:13 +1100
    Re: extracting a heapq in a for loop - there must be  more elegant solution Helmut Jarausch <jarausch@igpm.rwth-aachen.de> - 2013-12-04 09:44 +0000
      Re: extracting a heapq in a for loop - there must be  more elegant solution Cameron Simpson <cs@zip.com.au> - 2013-12-05 13:29 +1100
  Re: extracting a heapq in a for loop - there must be more elegant solution Ian Kelly <ian.g.kelly@gmail.com> - 2013-12-03 14:43 -0700
  Re: extracting a heapq in a for loop - there must be more elegant solution Ned Batchelder <ned@nedbatchelder.com> - 2013-12-03 17:32 -0500

csiph-web