Mensanator mensanator at aol.com
Sun Jul 12 15:47:46 EDT 2009

```On Jul 12, 2:11 pm, Cameron Pulsford <cameron.pulsf... at gmail.com>
wrote:
> Hey everyone, I have this small piece of code that simply finds the
> factors of a number.
>
> import sys
>
> def factor(n):
>      primes = (6*i+j for i in xrange(1, n) for j in [1, 5] if (i+j)%5 !
> = 0)
>
>      factors = []
>
>      for i in [2, 3, 5]:
>          while n % i == 0:
>              n /= i
>              factors.append(i)
>      for i in primes:
>          while n % i == 0:
>              n /= i
>              factors.append(i)
>      print factors
>
> factor(int(sys.argv[1]))
>
> My question is, is it possible to combine those two loops?

Yeah, get rid of the first loop.

> The primes
> generator I wrote finds all primes up to n, except for 2, 3 and 5, so
> I must check those explicitly. Is there anyway to concatenate the hard
> coded list of [2,3,5] and the generator I wrote so that I don't need
> two for loops that do the same thing?

primes.extend([2,3,5])

>
> I tried writing a primes function using yield statements, but it
> didn't work like I thought it would.

```