help with simple script and strings

[Kyle VanderBeek]

On Sat, Apr 12, 2008 at 04:52:06PM -0400, James Antill wrote:
>  You can't alter things that you are iterating, the easist fix is:
> 
> for directory in directories[:]:
> 
> ...the others being to create a new list of just what you want, or a
> list of what needs to go and then do the .remove() calls on that (these
> methods can be worth it, for large lists).

Actually, I'd contend this technique gets worse as your list size 
increases.  First, you're making a copy pass, doubling your memory 
footprint, and then a second pass to actually filter the list down to 
just the elements you want.  That will get slower as your list size 
increases.

Oh, and that reminds me of another way, using the builtin filter():

>>> directories = ['20080412', '20080324', 'blahblah', 'latest-dir',
'rawhide-20080410', 'rawhide-20080411', 'rawhide-20080412' , '20080401']
>>> filter(lambda x: x.startswith('200'), directories)
['20080412', '20080324', '20080401']


-- 
kylev at kylev.com
  Some people have a way with words, while others... erm... thingy.