merits of Lisp vs Python

[Jan Dries]

Alex Mizrahi wrote:
>  RB> Performance claims are always controversial. So, Python is much slower
>  RB> doing array multiplication, when you hand roll it, instead of using the
>  RB> standard numerical packages available.
> 
> heh, do you have "standard numeric packages" for everything? maybe then 
> we'll make standard programs for everything -- that will obsolete "slow" 
> "custom scripts" and we'll just use shell to select what program we want to 
> run?

I think you're missing the point. You must know your language's 
strengths and weaknesses, and use the approach/function/library that's 
right for the job in the given language.

For instance, on my machine the following Python-code:

     some_string = ""
     while len(some_string) < 100000:
         some_string += "*"

outperforms the following C-code:

     strcpy(some_string,"");
     while(strlen(some_string) < 100000)
         strcat(some_string,"*");

by roughly *factor 15*!

The point of course is you shouldn't be using strlen/strcat this way, 
nor use this piece of code as a reference for benchmarking C versus 
Python performance.
And for the same reason: in the presence of excellent optimized Python 
libraries for matrix multiplication, you probably shouldn't be doing 
that in pure Python if performance matters, nor use that as a reference 
case in benchmarking Python.

Regards,
Jan