benchmarks and questions for new python programmer

[stormslayer]

Folks:

I've been considering a shift to python.  I currently use c++builder
(borland) or perl.  I do computational models / statistics
programming, and was interested in python b/c it

a. has a library that connects to the R stats package
b. has code that seems way more readable than anything else

There is, however, at least for my work, a hard constraint.  Execution
time for large data sets / lots of iterations of a model needs to be
reasonabe.  So, I wrote a program to test it out (appended to the
bottom of this email).  As I said, this is my first python program. 
I'm sure it is terrible, but in many ways, you hope that the
interpreter / compiler corrects some errors (or the langauge isn't
that easy to use after all).

Benchmarks (for the paramter settings in the file):

C++builder 6.0: 3 seconds
Perl (ActivePerl 5.6.1.638): 14 seconds
Python (ActivePython 2.3.2 Build 232): 1 minute 13 seconds

Note that I didn't fiddle overmuch with any of the programs -- each
one took about 15 minutes to bang out on the keyboard.  I'm hoping
that there is some obvious mistake in the way I used something in
python to account for the speed differential.  It seems like a really,
really nice language, but orders of magnitude slower than C/C++ and a
5x slowdown over Perl seems abusive...

Thanks for any advice.  
sd


Python code:

#!/usr/bin/env python
import random

pop=[]      # popluation of agents; initially empty list
N = 10000     # population size
ep = .05    # mutation rate
its = 100   # number of times through the main loop
gold=0      # initial number of gold adopters; (1-gold) = silver
adopters
standard=0  # either 1 for gold or 2 for silver
shifts=0    # number of regime shifts 

def init_all():        # init globals
    global pop, gold, standard
    pop = []
    gold = 0
    for i in range(N):
        if random.randint(1,2) == 1:
            pop.append(1)
            gold=gold+1
        else: pop.append(2)
    if gold>N/2: standard=1
    else: standard=2        # if tie, silver wins
#    print "Initial Population of Gold Users: ", gold
# end function init_all

def one_choose():
    global pop, standard, gold, shifts
    for i in range(its):
        temp = random.randint(0,N-1)
        tempval = pop[temp]
        old_stand = standard
        if random.random()<ep:
            if random.random()<0.5:
                pop[temp]=1
                if tempval!=pop[temp]:
                    gold=gold+1
                    if gold>N/2: standard=1
            else:
                pop[temp]=2
                if tempval!=pop[temp]:
                    gold=gold-1
                    if gold<N/2: standard=2
        if standard!=old_stand: shifts=shifts+1 # check for regime
shift after each agent chooses anew
        else:
            if gold>N/2:
                if pop[temp]!=1:
                    pop[temp]=1
                    gold=gold+1
                    if gold>N/2: standard=1
            else:
                if pop[temp]!=2:
                    pop[temp]=2
                    gold=gold-1
                    if gold<N/2: standard=2
        if standard!=old_stand: shifts=shifts+1 # check for regime
shift after each agent chooses anew
#    print "Final Population of Gold Users: ", gold 
# end function one_choose

# start main loop


for i in range(1000):
    init_all()
    one_choose()
print "Number of regime shifts: ", shifts