Boyer-Moore and variants need a bit of preprocessing on the pattern which
makes them great for long patterns but more costly for short ones.
On Wed, 16 Feb 2005, Irmen de Jong wrote:
> Mike Brown wrote:
> > Fredrik Lundh wrote:
> >
> >>any special reason why "in" is faster if the substring is fo
Mike Brown wrote:
Fredrik Lundh wrote:
any special reason why "in" is faster if the substring is found, but
a lot slower if it's not in there?
Just guessing here, but in general I would think that it would stop searching
as soon as it found it, whereas until then, it keeps looking, which takes mo
> Assuming stringobject.c:string_contains is the right function, the
> code looks like this:
>
> size = PyString_GET_SIZE(el);
> rhs = PyString_AS_STRING(el);
> lhs = PyString_AS_STRING(a);
>
> /* optimize for a single character */
> if (size == 1)
>
On Wed, Feb 16, 2005 at 01:34:16PM -0700, Mike Brown wrote:
> time. But I would also hope that it would be smart enough to know that it
> doesn't need to look past the 2nd character in 'not the xyz' when it is
> searching for 'not there' (due to the lengths of the sequences).
Assuming stringobje
Fredrik Lundh wrote:
> any special reason why "in" is faster if the substring is found, but
> a lot slower if it's not in there?
Just guessing here, but in general I would think that it would stop searching
as soon as it found it, whereas until then, it keeps looking, which takes more
time. But
Title: RE: [Python-Dev] string find(substring) vs. substring in string
[Fredrik Lundh]
#- any special reason why "in" is faster if the substring is found, but
#- a lot slower if it's not in there?
Maybe because it stops searching when it finds it?
The time seems to be ve
any special reason why "in" is faster if the substring is found, but
a lot slower if it's not in there?
timeit -s "s = 'not there'*100" "s.find('not there') != -1"
100 loops, best of 3: 0.749 usec per loop
timeit -s "s = 'not there'*100" "'not there' in s"
1000 loops, best of 3: 0.122 use
