parenthesis

[Michele Simionato]

Lee Harr <missive at frontiernet.net> wrote in message news:<use8fo2je674ad at corp.supernews.com>...
> In article <2259b0e2.0211041224.7c24635b at posting.google.com>, 
> Michele Simionato wrote:
> > Suppose I want to parse the following expression:
> > 
> >>>> exp='(a*(b+c*(2-x))+d)+f(s1)'
> > 
> > I want to extract the first part, i.e. '(a*(b+c*(2-x))+d)'.
> > 
> 
> 
> n = 0
> for c in range(len(exp)):
>     l = exp[c]
>     if l == '(':
>         n += 1
>     elif l == ')':
>         n -= 1
>     if not n:
>         out = exp[0:c+1]
>         break
> print out

This is not the same that I did, indeed. Even if the logic is essentially the
same, you don't need to create the out list. It turns out the your approach
is 35% faster than mine, contrary to my naive expectations !

There-are-lies-damned-lies-and-benchmarks-ly yours,

                                                        Michele