Unexpected PendingDeprecationWarning

[Chris Angelico]

On Wed, Nov 23, 2016 at 2:14 PM, Nathan Ernst <nathan.ernst at gmail.com> wrote:
> I was not aware of that PEP.
>
> The logic in my function is exactly as desired, so to squelch the warning,
> I merely wrapped the iteration in a try/except:
>
> def adjacent_difference(seq, selector=identity):
>   i = iter(seq)
>   l = selector(next(i))
>   try:
>     while True:
>       r = selector(next(i))
>       yield r - l
>       l = r
>   except StopIteration:
>     return

You'll probably want to move the 'try' up one line - unless you want
an exception if the sequence is empty. And it's exactly this kind of
ambiguity that this change helps to catch.

ChrisA