How to remove subset from a file efficiently?

[Fredrik Lundh]

Steve Holden wrote:

> > looks like premature non-optimization to me...
> >
> It might be quicker to establish a dict whose keys are the barred
> numbers and use that, rather than a list, to determine whether the input
> numbers should make it through.

what do you think

>         barred = set(open('/home/sjd/python/wip/CBR0000319.dat'))

does ? ;-)

</F>