Path: csiph.com!x330-a1.tempe.blueboxinc.net!usenet.pasdenom.info!aioe.org!feeder.news-service.com!news2.euro.net!newsgate.cistron.nl!newsgate.news.xs4all.nl!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; 'else:': 0.03; 'variable,': 0.07; '__future__': 0.09; 'generators': 0.09; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:80.91.229.12': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'received:lo.gmane.org': 0.09; 'subject:string': 0.09; 'valueerror:': 0.09; 'def': 0.15; 'delimited': 0.16; 'martelli': 0.16; 'more:': 0.16; 'received:dip.t-dialin.net': 0.16; 'received:t-dialin.net': 0.16; 'subject:Processing': 0.16; 'wrote:': 0.16; 'processed': 0.18; 'memory': 0.21; 'wondered': 0.23; 'variable': 0.24; 'string': 0.26; 'separate': 0.28; 'import': 0.28; 'yield': 0.29; 'from:addr:web.de': 0.30; 'item,': 0.30; 'pattern': 0.30; 'separately.': 0.30; 'alex': 0.31; 'ps:': 0.32; 'break': 0.32; "what's": 0.33; 'to:addr:python-list': 0.33; 'like:': 0.34; 'limitations': 0.34; 'try:': 0.34; 'header:X -Complaints-To:1': 0.35; 'url:python': 0.36; 'url:pipermail': 0.37; 'run': 0.37; 'but': 0.37; 'could': 0.38; 'received:org': 0.38; 'url:org': 0.38; 'subject:: ': 0.39; 'header:Mime- Version:1': 0.39; "there's": 0.39; "couldn't": 0.39; 'to:addr:python.org': 0.39; 'might': 0.40; 'more': 0.60; 'relevant': 0.69; 'data?': 0.84; 'otten': 0.84
X-Injected-Via-Gmane: http://gmane.org/
To: python-list@python.org
From: Peter Otten <__peter__@web.de>
Subject: Re: Processing a large string
Date: Fri, 12 Aug 2011 16:48:10 +0200
Organization: None
References: <b16af723-854c-449d-8b45-565d73579e17@br5g2000vbb.googlegroups.com> <j22oqv$9ro$1@solani.org>
Mime-Version: 1.0
Content-Type: text/plain; charset="ISO-8859-1"
Content-Transfer-Encoding: 7Bit
X-Gmane-NNTP-Posting-Host: p5084b3bb.dip.t-dialin.net
X-BeenThere: python-list@python.org
X-Mailman-Version: 2.1.12
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.2220.1313160461.1164.python-list@python.org>
Lines: 40
NNTP-Posting-Host: 2001:888:2000:d::a6
X-Trace: 1313160461 news.xs4all.nl 23861 [2001:888:2000:d::a6]:55028
X-Complaints-To: abuse@xs4all.nl
Xref: x330-a1.tempe.blueboxinc.net comp.lang.python:11279

Peter Otten wrote:

> goldtech wrote:

>> Say I have a very big string with a pattern like:
>> 
>> akakksssk3dhdhdhdbddb3dkdkdkddk3dmdmdmd3dkdkdkdk3asnsn.....
>> 
>> I want to split the sting into separate parts on the "3" and process
>> each part separately. I might run into memory limitations if I use
>> "split" and get a big array(?)  I wondered if there's a way I could
>> read (stream?) the string from start to finish and read what's
>> delimited by the "3" into a variable, process the smaller string
>> variable then append/build a new string with the processed data?

> PS: This has come up before, but I couldn't find the relevant threads...

Alex Martelli a looong time ago:

> from __future__ import generators
> 
> def splitby(fileobj, splitter, bufsize=8192):
>     buf = ''
> 
>     while True:
>         try: 
>             item, buf = buf.split(splitter, 1)
>         except ValueError:
>             more = fileobj.read(bufsize)
>             if not more: break
>             buf += more
>         else:
>             yield item + splitter
> 
>     if buf:
>         yield buf

http://mail.python.org/pipermail/python-list/2002-September/770673.html