Testing for empty iterators?

Peter Otten __peter__ at web.de
Sun Jul 4 12:59:21 CEST 2004

Roy Smith wrote:

> Now I need to test to see if the iterator is empty.  Actually, it's a
> unit test where I want to assert that it is empty. In the old days, I
> would have done:
> assertEquals (getListOfThings (), [])
> but I don't see any clean way to do this with an iterator.  The best I

[and in a follow-up]

> Oh, never mind, I got it...
> assertEquals (list (getThingIterator ()), [])

An alternative would be

self.assertRaises(StopIteration, getThingIterator().next)

which is a bit stricter as it will choke if getThingIterator() returns a
list instead of an iterator.


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