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!newsfeed6.news.xs4all.nl!xs4all!post.news.xs4all.nl!not-for-mail
Date: Sun, 02 Sep 2012 09:51:15 -0400
From: Dave Angel <d@davea.name>
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:14.0) Gecko/20120714 Thunderbird/14.0
MIME-Version: 1.0
To: "John H. Li" <typetoken@gmail.com>
Subject: Re: Fwd: The method of insert doesn't work with nltk texts: AttributeError: 'ConcatenatedCorpusView' object has no attribute 'insert'
References: <58dd6730-9c37-4b90-9dbc-2724300ff5f4@googlegroups.com> <50433EA5.9090302@davea.name> <CAE5RzX=C7x-BXagCwANf+4wqb25eXKMkGs7TwMgSzciNFLDjew@mail.gmail.com> <CAE5RzXmbbOVd8ghoozrgAmQk1sgqVLAS=EVqpwvHPp-Tdiv3Cg@mail.gmail.com>
In-Reply-To: <CAE5RzXmbbOVd8ghoozrgAmQk1sgqVLAS=EVqpwvHPp-Tdiv3Cg@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
Cc: python-list@python.org
Precedence: list
Reply-To: d@davea.name
Newsgroups: comp.lang.python
Message-ID: <mailman.88.1346593882.27098.python-list@python.org>
Lines: 52
NNTP-Posting-Host: 2001:888:2000:d::a6
Xref: csiph.com comp.lang.python:28274

On 09/02/2012 09:06 AM, John H. Li wrote:
> First, thanks very much for your kind help.
>
> 1)Further more, I test the function of insert. It did work as follows:
>
>>>> text = ['The', 'Fulton', 'County', 'Grand']
>>>> text.insert(3,'like')
>>>> text
> ['The', 'Fulton', 'County', 'like', 'Grand']
> 2) I tested the text from nltk. It is list actually. See the following:
>>>> text = nltk.corpus.brown.words(categories = 'news')
>>>> text[:10]
> ['The', 'Fulton', 'County', 'Grand', 'Jury', 'said', 'Friday', 'an',
> 'investigation', 'of']
>
> How come python tells me that it is not a list by prompting "AttributeError:
> 'ConcatenatedCorpusView' object has no attribute 'insert'"? I am confused.
>
> Since we doubt text is not a list, I have to add one more line of code
> there as follows. Then it seems working.
>>>> text = nltk.corpus.brown.words(categories = 'news')
>>>> def hedge(text):
> text = list(text)
> for i in range(3,len(text),4):
>  text.insert(i, 'like')
> return text[:50]
>
>>>> hedge(text)
> ['The', 'Fulton', 'County', 'like', 'Grand', 'Jury', 'said', 'like',
> 'Friday', 'an', 'investigation', 'like', 'of', "Atlanta's", 'recent',
> 'like', 'primary', 'election', 'produced', 'like', '``', 'no', 'evidence',
> 'like', "''", 'that', 'any', 'like', 'irregularities', 'took', 'place',
> 'like', '.', 'The', 'jury', 'like', 'further', 'said', 'in', 'like',
> 'term-end', 'presentments', 'that', 'like', 'the', 'City', 'Executive',
> 'like', 'Committee', ',']
>
> Isn't it odd?
>
>

Without reading the documentation, or at least the help(), I can't
figure it to be odd.  If a class wants to support slicing semantics, all
it has to do is implement special methods like __getslice__ and
__setslice__.  If it doesn't document .insert(), then you shouldn't try
to call it.  Duck-typing.

What did you get when you tried type(), dir() and help() ?  Did they help.

-- 

DaveA