iterator-with-exception

 def iter_except(func, exc_class, first=None):
     try:
         if first is not None:
             yield first()
         while 1:
             yield func()
     except exc_class:
         pass
 
Samples:

>>> elements = set([1, 2, 3, 4, 5])
>>> iterator = iter_except(elements.pop, KeyError)
>>> iterator.next()
1
>>> elements
set([2, 3, 4, 5])
>>> list(iterator)
[2, 3, 4, 5]
>>> elements
set([])