Initial port of Goop.java, not fully moved over and serious performance issues

goop.py

#!/usr/bin/env python
import random
from pyglet.image import ImageData 
from pyglet.window import *

w = 320 
h = 320 
window = pyglet.window.Window()
window.set_size(w,h)
img = pyglet.image.create(w,h)
data = [int(255*random.random()) for i in xrange(w*h*4)]

def goop(dt):
  global img
  global data
  for i in range(w*2,(w*h*4)-w*2):
    if int(500*random.random()) < 1:
      r = int(255*random.random())
      data[i] = r 
      data[i-1] = r 
      data[i-2] = r 
      data[i-3] = r
      data[i-4] = r
    d = data[i]
    d += data[i + 4]
    d += data[i - 4] 
    d += data[i - 8] 
    d += data[i + 8] 
    d += data[i - w]
    d += data[i + w]
    d = d / 7 
    if(data[i] > 150):
      d += data[i + w * 2]
      d = d / 2 
      data[i + w * 2] = d
      data[i + w] = d
    elif(data[i] < 125): 
      d += data[i - w * 2]
      d = d / 2 
      data[i - w * 2] = d
      data[i - w] = d
    data[i] = d

@window.event
def on_draw():
  window.clear() 
  global img
  global data
  img.set_data('RGBA',w*4,''.join(map(chr, data)));
  img.blit(0,0,0)

pyglet.clock.schedule_interval(goop, .1) 
pyglet.app.run()