Path: csiph.com!usenet.pasdenom.info!gegeweb.org!de-l.enfer-du-nord.net!feeder1.enfer-du-nord.net!feeds.phibee-telecom.net!newsfeed.xs4all.nl!newsfeed5.news.xs4all.nl!xs4all!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 0.001
X-Spam-Evidence: '*H*': 1.00; '*S*': 0.00; 'nested': 0.07; "subject:' ": 0.07; 'though:': 0.07; 'python': 0.09; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'bug': 0.10; 'subject:not': 0.11; 'options.': 0.15; 'received:80.91.229.3': 0.16; 'received:plane.gmane.org': 0.16; 'route,': 0.16; 'subject:item': 0.16; 'subject:object': 0.16; 'wrote:': 0.17; 'fix': 0.17; 'code.': 0.20; 'tracker': 0.20; 'subject:support': 0.22; 'work.': 0.23; 'raise': 0.24; 'header:In-Reply-To:1': 0.25; 'header:User- Agent:1': 0.26; 'looks': 0.26; 'header:X-Complaints-To:1': 0.28; '>>>>': 0.29; 'statements': 0.29; 'code': 0.31; 'from:addr:yahoo.co.uk': 0.32; 'print': 0.32; 'to:addr:python- list': 0.33; 'likely': 0.33; 'another': 0.33; 'list': 0.35; 'there': 0.35; 'list.': 0.35; 'received:org': 0.36; 'created': 0.36; 'does': 0.37; 'option': 0.37; 'item': 0.37; 'data': 0.37; 'mark': 0.38; 'object': 0.38; 'to:addr:python.org': 0.39; 'header:Received:5': 0.40; 'your': 0.60; 'is.': 0.62; 'forward': 0.66; 'received:2': 0.91
X-Injected-Via-Gmane: http://gmane.org/
To: python-list@python.org
From: Mark Lawrence <breamoreboy@yahoo.co.uk>
Subject: Re: 'str' object does not support item assignment
Date: Sun, 23 Sep 2012 20:11:05 +0100
References: <ec85c16b-086b-4b43-aba3-70a05f34cf69@googlegroups.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
X-Gmane-NNTP-Posting-Host: host-2-97-77-28.as13285.net
User-Agent: Mozilla/5.0 (Windows NT 6.0; rv:15.0) Gecko/20120907 Thunderbird/15.0.1
In-Reply-To: <ec85c16b-086b-4b43-aba3-70a05f34cf69@googlegroups.com>
X-Antivirus: avast! (VPS 120923-0, 23/09/2012), 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.1150.1348427460.27098.python-list@python.org>
Lines: 24
NNTP-Posting-Host: 2001:888:2000:d::a6
X-Trace: 1348427460 news.xs4all.nl 6915 [2001:888:2000:d::a6]:56026
X-Complaints-To: abuse@xs4all.nl
Xref: csiph.com comp.lang.python:29851

On 23/09/2012 19:31, jimbo1qaz wrote:
> spots[y][x]=mark fails with a "'str' object does not support item assignment" error,even though:
>>>> a=[["a"]]
>>>> a[0][0]="b"
> and:
>>>> a=[["a"]]
>>>> a[0][0]=1000000
> both work.
> Spots is a nested list created as a copy of another list.
>

Looks to me as if there are three options.
a) raise a bug report on the Python bug tracker at bugs.python.org.
b) fix your code.

As option b) is the likely route, the way forward is to put print 
statements in your code so you can see what data you have *AND* what 
type it is.

-- 
Cheers.

Mark Lawrence.