where python is slower?

[Just]

In article <mailman.1044449190.18425.python-list at python.org>,
 "Enrique Palomo" <enrique.palomo at xgs-spain.com> wrote:

> At job, i must work with great size text files (up to 2 Gb)
> I use python cause of its facility to work with strings.
> But python is slower than others programming languages.
> 
> It´s not, by the moment, a big problem, but i would like to speed up the
> code with C.
> 
> I would like to know where python is slower, reading files, writing, string
> manipulation...
> 
> I have try with psyco and the results are unpredictable everytime i run the
> script.

If you're reading the files line by line you need to carefully look at 
what idiom you use to do that. If you're using Python2.2, you're 
_probably_ best off by doing this:

   f = open(...)
   for line in f:
      ...process line...

In earlier Pythons (prabably back to 2.0, not sure) you the equivalent 
is:

   f = open(...)
   for line in f.xreadlines():
      ...process line...

Using f.readline() one line at a time is likely to be noticably slower, 
unless the bottleneck is your actual processing...

Just