python vs perl performance test

[igor.tatarinov at gmail.com]

First, let me admit that the test is pretty dumb (someone else
suggested it :) but since I am new to Python, I am using it to learn
how to write efficient code.

my $sum = 0;
foreach (1..100000) {
    my $str = chr(rand(128)) x 1024;
    foreach (1..100) {
        my $substr = substr($str, rand(900), rand(100));
        $sum += ord($substr);
    }
}
print "Sum is $sum\n";

Basically, the script creates random strings, then extracts random
substrings, and adds up the first characters in each substring. This
perl script takes 8.3 secs on my box and it can probably be improved.

When I first translated it to Python verbatim, the Python script took
almost 30 secs to run.
So far, the best I can do is 11.2 secs using this:

from random import randrange
from itertools import imap, repeat
from operator import getitem, add, getslice

result = 0
zeros = [0]*100
for i in xrange (100000):
    s = [chr(randrange(128))] * 1024
    starts = repeat(randrange(900), 100)
    ends = imap(add, starts, repeat(randrange(1,100), 100))
    substrs = imap(getslice, repeat(s, 100), starts, ends)
    result += sum(imap(ord, imap(getitem, substrs, zeros)))

print "Sum is ", result

There's got to be a simpler and more efficient way to do this.
Can you help?

Thanks,
igor