Path: csiph.com!fu-berlin.de!uni-berlin.de!not-for-mail
From: Peter Otten <__peter__@web.de>
Newsgroups: comp.lang.python
Subject: Re: Writing different sections into a file
Date: Mon, 25 Apr 2016 10:48:39 +0200
Organization: None
Lines: 31
Message-ID: <mailman.67.1461574128.32212.python-list@python.org>
References: <ad6f9260-0c01-4246-9be5-84b1d2470255@googlegroups.com> <nfkll8$va5$1@ger.gmane.org>
Mime-Version: 1.0
Content-Type: text/plain; charset="ISO-8859-1"
Content-Transfer-Encoding: 7Bit
X-Trace: news.uni-berlin.de DZdXx/z7woUtxKwNsvskHAkFQOgRwvSwiOme+KZJ1bpQ==
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; 'subject:file': 0.07; '"w")': 0.09; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'subject:Writing': 0.09; 'subject:into': 0.09; 'advance': 0.10; 'sections': 0.13; 'section.': 0.15; 'fits': 0.16; 'received:80.91.229.3': 0.16; 'received:dip0.t-ipconnect.de': 0.16; 'received:io': 0.16; 'received:plane.gmane.org': 0.16; 'received:psf.io': 0.16; 'received:t-ipconnect.de': 0.16; 'wrote:': 0.16; 'memory': 0.17; 'body,': 0.22; 'file.': 0.22; 'header': 0.24; 'header:User-Agent:1': 0.26; 'header:X-Complaints- To:1': 0.26; 'dictionary': 0.29; 'point': 0.33; 'url:python': 0.33; 'file': 0.34; 'this?': 0.34; 'list': 0.34; 'url:dev': 0.35; 'url:org': 0.36; 'url:library': 0.36; 'to:addr:python-list': 0.36; 'subject:: ': 0.37; 'received:org': 0.37; 'list.': 0.37; 'data': 0.39; 'format': 0.39; 'easily': 0.39; 'to:addr:python.org': 0.40; 'received:de': 0.40; 'body': 0.61; 'per': 0.62; 'different': 0.63; 'choose': 0.68; 'url:configparser': 0.84
X-Injected-Via-Gmane: http://gmane.org/
X-Gmane-NNTP-Posting-Host: p57bd9f11.dip0.t-ipconnect.de
User-Agent: KNode/4.13.3
X-BeenThere: python-list@python.org
X-Mailman-Version: 2.1.22
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>
X-Mailman-Original-Message-ID: <nfkll8$va5$1@ger.gmane.org>
X-Mailman-Original-References: <ad6f9260-0c01-4246-9be5-84b1d2470255@googlegroups.com>
Xref: csiph.com comp.lang.python:107588

Palpandi wrote:

> I need to write different sections into a file.
> At any point of time, content can be added to any section.
> 
> I don't want keep each section into a temporary file.
> What is the better way to store the contents of each section and write
> them into a file at the end? What is the better datatype to achieve this?

If the data easily fits into memory just keep it in one list per section

header = [...]
body = [...]
footer = [...]

...
body.append("something more\n")
footer[:] = ["new footer\n"]
...

with open(filename, "w") as f:
    for section in (header, body, footer):
        f.writelines(section)


If the sections are not known in advance put them into a dictionary or a 
list.

If you are free to choose the file format you may use
https://docs.python.org/dev/library/configparser.html