Python 2 times slower than Perl

[James Logajan]

Ewald van Houte wrote:
[ Parts elided for brevity. ]
> xucs007 at yahoo.com (Xu, C.S.) wrote
> > #!/usr/bin/env python
> > i = 2.5;
> > while i < 1e7:
> >         j = 2.5 * 2.5
> >         i += 1
> > print i, j
> >
> > The `time` results on my PII 450M is:
> >      python script:     37.93u 0.03s 0:38.03 99.8%
> >      perl script:     15.36u 0.03s 0:15.42 99.8%
> >      java compiled:     1.07u 0.10s 0:01.20 97.5%
> >      C compiled:     0.24u 0.01s 0:00.25 100.0%
> 
> Tried the same with for loop and while loop
> 
> def f1():
>         i=2.5
>         while i<1e7:
>                 j=2.5*2.5
>                 i+=1
>         print i,j
> 
> def f3():
>         i=2.5
>         for i in xrange(2.5,1e7+1):
>                 j=2.5*2.5
>         print i,j
> 
> Results
> f1()            34.5 seconds
> f3()            18.8 seconds
> 
> some improvement but f3() will still be slower than Perl version (~30%)

You forgot to normalize your result with his by using the results of f1():

>>> 15.36/(18.8*(34.5/37.93))
0.898249768733

Only about 10% slower.