Why is Python so slow?

Peter Schneider-Kamp petersc at stud.ntnu.no
Sun Jun 18 17:14:11 EDT 2000


William Dandreta wrote:
> 
> I posted a message a while ago about a Python script I wrote that took 90
> mins to run when a similar job in C++ took only 2 mins.
> 
> With help from some experts in this news group, most notably, Peter
> Schneider-Kamp, I was able to reduce the time to 37 mins

Thanks, but I don't deserve that title ;)

> Today I was looking at the script and I noticed that the only string
> function I was using that was not in strop was replace. I took a look at it
> and found:
> 
> replace(x,y) = joinfields(splitfields(x,y),'')
> 
> When I replaced, replace with the joinfields(splitfields()) in strop, much
> to my surprise, the time for the job dropped to 6 minutes.

In my Python version (post 1.6a2 CVS) the joinfields/splitfields
solution
caused double the number of function calls (naturally...) and ran almost
half as fast the replace version.

BTW: You probably meant:

replace(x,y,z) = joinfields(splitfields(x,y),z)

Bye
Peter 
--
Peter Schneider-Kamp          ++47-7388-7331
Herman Krags veg 51-11        mailto:peter at schneider-kamp.de
N-7050 Trondheim              http://schneider-kamp.de




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