Re: A gnarly little python loop

Path	csiph.com!usenet.pasdenom.info!weretis.net!feeder4.news.weretis.net!news.mixmin.net!feeder.erje.net!eu.feeder.erje.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	<showell30@yahoo.com>
X-Original-To	python-list@python.org
Delivered-To	python-list@mail.python.org
X-Spam-Status	OK 0.002
X-Spam-Evidence	'H': 1.00; 'S': 0.00; 'else:': 0.03; 'api.': 0.04; 'chunk': 0.07; 'api': 0.09; "%s'": 0.09; 'page)': 0.09; 'to:addr:comp.lang.python': 0.09; 'cc:addr:python-list': 0.10; 'def': 0.10; 'subject:python': 0.11; '%d,': 0.16; '1):': 0.16; 'inaccessible': 0.16; 'itertools': 0.16; 'simpson': 0.16; 'simulate': 0.16; 'wrote:': 0.17; 'skip:i 40': 0.17; "i'd": 0.22; 'cc:20': 0.23; 'cc:no real name:20': 0.24; 'paul': 0.24; 'testing': 0.24; 'cc:addr:python.org': 0.25; 'header:In-Reply- To:1': 0.25; 'header:User-Agent:1': 0.26; 'writes:': 0.29; 'code': 0.31; 'print': 0.32; 'goes': 0.33; '11,': 0.33; 'version:': 0.33; 'version': 0.34; 'received:google.com': 0.34; 'too.': 0.35; 'received:209.85': 0.35; 'but': 0.36; 'test': 0.36; 'received:209': 0.37; 'data': 0.37; 'subject:: ': 0.38; 'page': 0.38; 'received:209.85.214': 0.39; 'first': 0.61; 'improved': 0.62; 'times': 0.63; 'here': 0.65; 'otten': 0.84; 'received:209.85.214.184': 0.84; 'received:mail- ob0-f184.google.com': 0.84; 'succession': 0.84
Newsgroups	comp.lang.python
Date	Sun, 11 Nov 2012 09:16:06 -0800 (PST)
In-Reply-To	<mailman.3557.1352627686.27098.python-list@python.org>
Complaints-To	groups-abuse@google.com
Injection-Info	glegroupsg2000goo.googlegroups.com; posting-host=199.27.178.37; posting-account=siT9MAoAAABdTBQh0iQ6NHgnerF0yiR-
References	<k7nlmo$1v6$2@ger.gmane.org> <mailman.3555.1352623728.27098.python-list@python.org> <7x4nkwzesu.fsf@ruckus.brouhaha.com> <mailman.3557.1352627686.27098.python-list@python.org>
User-Agent	G2/1.0
X-Google-Web-Client	true
X-Google-IP	199.27.178.37
MIME-Version	1.0
Subject	Re: A gnarly little python loop
From	Steve Howell <showell30@yahoo.com>
To	comp.lang.python@googlegroups.com
Content-Type	text/plain; charset=ISO-8859-1
Cc	python-list@python.org
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>
Message-ID	<mailman.3561.1352654170.27098.python-list@python.org> (permalink)
Lines	73
NNTP-Posting-Host	2001:888:2000:d::a6
X-Trace	1352654170 news.xs4all.nl 6931 [2001:888:2000:d::a6]:58113
X-Complaints-To	abuse@xs4all.nl
Xref	csiph.com comp.lang.python:33133

Show key headers only | View raw

On Sunday, November 11, 2012 1:54:46 AM UTC-8, Peter Otten wrote:
> Paul Rubin wrote:
> 
> 
> 
> > Cameron Simpson <cs@zip.com.au> writes:
> 
> >> | I'd prefer the original code ten times over this inaccessible beast.
> 
> >> Me too.
> 
> > 
> 
> > Me, I like the itertools version better.  There's one chunk of data
> 
> > that goes through a succession of transforms each of which
> 
> > is very straightforward.
> 
> 
> 
> [Steve Howell]
> 
> >     def get_tweets(term, get_page):
> 
> >         page_nums = itertools.count(1)
> 
> >         pages = itertools.imap(api.getSearch, page_nums)
> 
> >         valid_pages = itertools.takewhile(bool, pages)
> 
> >         tweets = itertools.chain.from_iterable(valid_pages)
> 
> >         return tweets
> 
>  
> 
> 
> 
> But did you spot the bug(s)?
> 

My first version was sketching out the technique, and I don't have handy access to the API.

Here is an improved version:

    def get_tweets(term):
        def get_page(page):
            return getSearch(term, page)
        page_nums = itertools.count(1)
        pages = itertools.imap(get_page, page_nums)
        valid_pages = itertools.takewhile(bool, pages)
        tweets = itertools.chain.from_iterable(valid_pages)
        return tweets

    for tweet in get_tweets("foo"):
            process(tweet)

This is what I used to test it:


    def getSearch(term = "foo", page = 1):
        # simulate api for testing
        if page < 5:
            return [
                'page %d, tweet A for term %s' % (page, term),
                'page %d, tweet B for term %s' % (page, term),
            ]
        else:
            return None

    def process(tweet):
        print tweet

Thread

Re: A gnarly little python loop Cameron Simpson <cs@zip.com.au> - 2012-11-11 19:48 +1100
  Re: A gnarly little python loop Paul Rubin <no.email@nospam.invalid> - 2012-11-11 01:09 -0800
    Re: A gnarly little python loop Peter Otten <__peter__@web.de> - 2012-11-11 10:54 +0100
      Re: A gnarly little python loop Steve Howell <showell30@yahoo.com> - 2012-11-11 09:16 -0800
      Re: A gnarly little python loop Steve Howell <showell30@yahoo.com> - 2012-11-11 09:16 -0800
    Re: A gnarly little python loop Steve Howell <showell30@yahoo.com> - 2012-11-11 09:29 -0800
      Re: A gnarly little python loop Peter Otten <__peter__@web.de> - 2012-11-11 19:34 +0100
        Re: A gnarly little python loop Steve Howell <showell30@yahoo.com> - 2012-11-11 11:16 -0800
          Re: A gnarly little python loop Cameron Simpson <cs@zip.com.au> - 2012-11-12 11:43 +1100
            Re: A gnarly little python loop Steve Howell <showell30@yahoo.com> - 2012-11-11 17:38 -0800
        Re: A gnarly little python loop Roy Smith <roy@panix.com> - 2012-11-11 14:23 -0500

csiph-web