Re: [Python-ideas] Function to return first(or last) true value from list

אלעזר wrote:

What is the "classic" use case for next() raising StopIteration, to be silently caught ? We need __next__ to do so in for loops, but when do we need it in the functional form?

Pretty much every generator that treats the first item(s) specially, like the one I gave above:

...

def process_source(source): it = iter(source) first = next(it) for item in it: yield first * item

Or these: http://docs.python.org/dev/library/itertools.html#itertools.accumulate http://docs.python.org/dev/library/itertools.html#itertools.groupby http://docs.python.org/dev/library/itertools.html#itertools.islice ... The behaviour of next() is really a feature rather than a bug.