継ぎ足しの秘伝のタレは割とすぐに元のタレじゃなくなるらしい

import random

# field value: 0=void, 1=first gen, 2=other
field = [1 for _ in range(0, 500*500)] 
gen = 0
cnt = 500*500
use_amount = 25

def setup():
    size(500, 500)
    background(0)
    noStroke()

def draw():
    background(0)
    show()
    use()
    add_on()
    mix()
    delay(100)

def show():
    count = 0

    for y in range(0, height):
        for x in range(0, width):

            if (field[y*width+x] == 1):
                count += 1
                fill(255, 0, 0)

            else:
                fill(0, 0, 255)

            rect(x, y, 1, 1)

    global cnt
    cnt = count

def use():
    global use_amount

    for i in range(width*use_amount):
        field[i] = 0

def add_on():
    global cnt
    global gen
    global use_amount

    gen = gen + 1

    print("gen: "+ str("{:3d}".format(gen)) +
          ", ratio: " + str("{:.3f}".format(cnt*1.0/width/height*100)) + "%")

    for i in range(width*use_amount):
        field[i] = 2

def mix():
    random.shuffle(field)