[Python-ideas] sentinel_exception argument to `iter`

[Yury Selivanov]

On 2/6/2014, 7:10 PM, Ram Rachum wrote:
> Hi,
>
> This time I'm posting on the right list :) Sorry for the mistake in the
> last thread.
>
> `iter` has a very cool `sentinel` argument. I suggest an additional
> argument `sentinel_exception`; when it's supplied, instead of waiting for a
> sentinel value, we wait for a sentinel exception to be raised, and then the
> iteration is finished.
>
> This'll be useful to construct things like this:
>
>      my_iterator = iter(my_deque.popleft, IndexError)
>
Before starting discussion about the new parameter:
how passing 'my_deque.popleft' is supposed to work?

Yury