?

[Paul Hankin]

On May 17, 11:08 am, Ruediger <larud... at freenet.de> wrote:
> urikaluzhny wrote:
> > It seems that I rather frequently need a list or iterator of the form
> > [x for x in <> while <>]
> > And there is no one like this.
> > May be there is another short way to write it (not as a loop). Is
> > there?
> > Thanks
>
> I usually have the same problem and i came up with an solution like that:
>
> from operator import ne
> def test(iterable, value, op=ne):
>     _n = iter(iterable).next
>     while True:
>         _x = _n()
>         if op(_x, value):
>             yield _x
>         else:
>             raise StopIteration

This is better written using takewhile...
itertools.takewhile(lambda x: x != value, iterable)

But if you really need to reinvent the wheel, perhaps this is simpler?

def test(iterable, value, op=operator.ne):
    for x in iterable:
        if not op(x, value):
            return
        yield x

--
Paul Hankin