[Python-Dev] Re: Sets: elt in dict, lst.include

[Guido van Rossum]

> Not really.  Available time is finite, and this isn't at the top of the list
> of things I'd like to see (resuming the discussion of generators +
> coroutines + iteration protocol comes to mind first).

OK, get going on that one then!

> >> Cool!  Can we resist adding
> >>
> >>     if key:value in dict
> >>
> >> for "parallelism"?  (I know I can ...)
> 
> > That's easy to resist because, unlike ``for key:value in dict'', it's
> > not unambiguous:
> 
> But
> 
>     if (key:value) in dict
> 
> is.  Just trying to help whoever *does* want the PEP <wink>.

OK, I'll pronounce -1 on this one.  It looks ugly to me -- too
reminiscent of C's if (...) required parentheses.  Also it suggests
that (key:value) is a new tuple notation that might be useful in other
contexts -- which it's not.

> > ...
> > I'm certainly more comfortable with just ``for key in dict'' than with
> > the whole slow of extensions using colons.
> 
> What about just the
> 
>     for key:value in dict
>     for index:value in sequence
> 
> extensions?

I'm not against these -- I'd say +0.5.

> The degenerate forms (omitting x or y or both in x:y) are
> mechanical variations so are likely to get raised.

For those, +0.2.

> > But, again, that's for the PEP to fight over.
> 
> PEPs are easier if you Pronounce on things you hate early so that those can
> get recorded in the "BDFL Pronouncements" section without further ado.

At your service -- see above.

--Guido van Rossum (home page: http://www.python.org/~guido/)