On Wednesday, June 22, 2011 4:10:39 PM UTC-7, Neal Becker wrote:
> AFAIK, the above is the only python idiom that allows iteration over a
> sequence
> such that you can write to the sequence. And THAT is the problem. In many
> cases, indexing is much less efficient than iteration.
Well, if your program is such that you can notice a difference between indexing
and iteration, you probably have better things to worry about. But whatever.
You can get the effect you're asking for like this:
class IteratorByProxy(object):
def __init__(self,iterable):
self.set(iterable)
def __iter__(self):
return self
def next(self):
return self.current_iter.next()
def set(self,iterable):
self.current_iter = iter(iterable)
s = IteratorByProxy(xrange(10))
for i in s:
print i
if i == 6:
s.set(xrange(15,20))
Carl Banks
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