[Tutor] Re: primes

[André Roberge]

jfouhy at paradise.net.nz wrote:
> Quoting Gregor Lingl <glingl at aon.at>:
> 
> 
>>[x for x in range(2,100) if not [y for y in range(2,x) if x%y==0]]
> 
> 
> Heh.  That's quite neat.
> 
> I can only offer one suggestion --- if you replace range with xrange, you get a
> small speed improvement.
> 
> eg: On my system, it took 415 seconds to generate a list of primes < 50,000
> using range, but only 386 seconds if I use the same code, but with xrange instead.
> 
What about using something like range(2, math.sqrt(x)) instead?