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From: "Frank Millman" <frank@chagford.com>
Newsgroups: comp.lang.python
Subject: Re: Cannot step through asynchronous iterator manually
Date: Sat, 30 Jan 2016 15:45:51 +0200
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"Oscar Benjamin"  wrote in message 
news:CAHVvXxSA0Yq4VOYy6qycgXxVpL5zZGM8muUi+1VmeZD8CRgtvg@mail.gmail.com...
>
> The simplest thing would just be to call list(cur) but I realise that
you don't want to consume more than 2 rows from the database so just
use islice:
>
> rows = list(islice(cur, 2))  # pull at most 2 rows
> if not rows:
>     # no rows
> elif len(rows) > 1:
>     # too many rows
> row = rows[0]
>

I like the idea, but I don't think it would work with an asychronous 
iterable. OTOH it should not be difficult to roll your own using the example 
in the itertools docs as a base. Except that the example uses next(it) 
internally, and this thread started with the fact that there is no 
asychronous equivalent, so I might be back to square one.

But these are all variations on a similar theme, so I don't think it matters 
which one I choose. I will go through them at my leisure and pick the most 
readable one.

Thanks

Frank