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Date: Mon, 12 Nov 2012 20:14:04 -0800 (PST)
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Subject: Re: A gnarly little python loop
From: rusi <rustompm...@gmail.com>
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On Nov 12, 9:09=A0pm, Steve Howell <showel...@yahoo.com> wrote:
> On Nov 12, 7:21=A0am, rusi <rustompm...@gmail.com> wrote:
>
> > On Nov 12, 12:09=A0pm, rusi <rustompm...@gmail.com> wrote:> This is a c=
lassic problem -- structure clash of parallel loops
>
> > <rest snipped>
>
> > Sorry wrong solution :D
>
> > The fidgetiness is entirely due to python not allowing C-style loops
> > like these:
>
> > >> while ((c=3Dgetchar()!=3D EOF) { ... }
> > [...]
>
> There are actually three fidgety things going on:
>
> =A01. The API is 1-based instead of 0-based.
> =A02. You don't know the number of pages in advance.
> =A03. You want to process tweets, not pages of tweets.
>
> Here's yet another take on the problem:
>
> =A0 =A0 # wrap fidgety 1-based api
> =A0 =A0 def search(i):
> =A0 =A0 =A0 =A0 return api.GetSearch("foo", i+1)
>
> =A0 =A0 paged_tweets =3D (search(i) for i in count())
>
> =A0 =A0 # handle sentinel
> =A0 =A0 paged_tweets =3D iter(paged_tweets.next, [])
>
> =A0 =A0 # flatten pages
> =A0 =A0 tweets =3D chain.from_iterable(paged_tweets)
> =A0 =A0 for tweet in tweets:
> =A0 =A0 =A0 =A0 process(tweet)

[Steve Howell]
Nice on the whole -- thanks
Could not the 1-based-ness be dealt with by using count(1)?
ie use
paged_tweets =3D (api.GetSearch("foo", i) for i in count(1))

{Peter]
> >>> while ((c=3Dgetchar()!=3D EOF) { ... }

for c in iter(getchar, EOF):
    ...

Thanks. Learnt something