a list/re problem

[Nobody]

On Fri, 11 Dec 2009 12:49:42 -0800, Ed Keith wrote:

> the following works:
> 
> r = re.compile('\*(.+)\*')
> 
> def f(s):
>     m = r.match(s)
>     if m:
>         return m.group(1)
>     else:
>         return ''
> 	
> n =  [f(x) for x in l if r.match(x)]
> 
> 
> 
> But it is inefficient, because it is matching the regex twice for each
> item, and it is a bit ugly. 

> Does anyone have a better solution?

Use a language with *real* list comprehensions?

Flamebait aside, you can use another level of comprehension, i.e.:

	n = [m.group(1) for m in (r.match(x) for x in l) if m]