x.py

import itertools
from PIL import Image

img = Image.new("RGB", (10, 10))
pixels = img.load()

for i, j in itertools.product(xrange(10), xrange(10)):
    if (i + j) % 2 == 0:
        pixels[i, j] = (0, 0, 0)
    else:
        pixels[i, j] = (255, 255, 255)

img.show()