[Python-ideas] Generator syntax hooks?

Steven D'Aprano steve at pearwood.info
Fri Aug 11 01:18:34 EDT 2017


On Fri, Aug 11, 2017 at 02:49:10PM +1000, Steven D'Aprano wrote:
> On Thu, Aug 10, 2017 at 01:25:24PM -0700, Chris Barker wrote:

> > I guess I think of it like this:
> > 
> > "if" is providing a filtering mechanism
> > 
> > "while" is providing a termination mechanism
> > 
> >  -- is there a use case anyone can think of when they would want the while
> > to be applied to the list AFTER filtering?


Oops, sorry I had a thinko and read your question in the opposite sense 
than it actually is. See my response to Nick for an example:

I have an iterable of arbitrary objects. I want to ignore anything that
isn't a string, and halt if the string doesn't start with "A".

[expr for s in objects if isinstance(s, str) while s.startswith("A")]


-- 
Steve


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