I don't think it's a stupid question at all. =]. But wouldn't it solve the problem if you call the generator the first time you need it to yield?
Cheers, Xav On Fri, Feb 19, 2010 at 9:30 AM, Robert Kern <robert.k...@gmail.com> wrote: > On Feb 18, 5:08 pm, Steven D'Aprano <st...@remove-this-cybersource.com.au> > wrote: > > On 2010-02-18 16:25 PM, Stephen Hansen wrote: > > > > > This has to be a stupid question, but :) > > > > > I have some generators that do stuff, then start yielding results. On > > > occasion, I don't want them to yield anything ever-- they're only > > > really "generators" because I want to call them /as/ a generator as > > > part of a generalized system. > > > > > The only way I can figure out how to make an empty generator is: > > > > > def gen(): > > > # do my one-time processing here > > > > > return > > > yield > > > > If all you want is a generator that doesn't yield anything, then surely > > there isn't any one-time processing and you don't need the comment? > > Sure there is. Python doesn't know that nothing gets yielded until it hits > the return statement before the yield. When it calls .next() on the > iterator, the code elided by the comment executes, then the return is hit, a > StopIteration exception is raised, and the iteration is complete. > > > -- > Robert Kern > > "I have come to believe that the whole world is an enigma, a harmless > enigma > that is made terrible by our own mad attempt to interpret it as though it > had > an underlying truth." > -- Umberto Eco > > -- > http://mail.python.org/mailman/listinfo/python-list >
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