draws Sierpinski triangle

sier.py

"""
    Draws a Sierpinski triangle (using PIL library)
    result (using 2**13 rows = 8192 x 8192): http://i.imgur.com/qFkI9Yu.png
"""

rows_to_write = 2**11


def gen_rows(n_rows):
    r = 1
    for i in range(n_rows):
        yield r
        # python handles big integers, no need for string version
        r = (r << 1) ^ r

int_rows = gen_rows(rows_to_write)
rows = [bin(r)[2:] for r in int_rows]
max_width = max([len(r) for r in rows])

centered = [r.center(max_width, '0') for r in rows]

colors = {
    '1': 0x0,
    '0': 0xFFFFFF,
}

pixels = [colors[px] for row in centered for px in row]

from PIL import Image

img = Image.new('RGB', (max_width, rows_to_write))
img.putdata(pixels)
img.save('sierpinski.png')