My (late) beef with Simple Generator syntax (PEP 255)

[sismex01 at hebmex.com]

> From: Cameron Horn [mailto:camhorn at mac.com]
> Sent: Wednesday, November 13, 2002 4:20 PM
>  
> On Wednesday, Nov 13, 2002, at 02:16PM, David Eppstein 
> <eppstein at ics.uci.edu> wrote:
> 
> >On 11/13/02 2:11 PM -0800 Cameron Horn <camhorn at mac.com> wrote:
> >>> What I wonder is, why does it need to be a generator?  
> What's wrong with
> >>> def foo(): return ( )
> >>> ?
> >>
> >> You're right if it's a one-time thing.  However, if I've got a
> >> scaffolding like this, then it matters.
> >>
> >> def process_generator(function):
> >>    for x in function():
> >>       print x
> >
> >How does the function foo() I defined above fail to work in this 
> >scaffolding?
> 
> In the "TypeError: iteration over non-sequence" sort of way.
>

An empty tuple is a sequence also;

the "return ( )" thing is returning an empty tuple,
not "None".  You can make it clearer by using
"return tuple()" rather than "return ()".

-gustavo