@anniek_p 's mindblowingly simple yet fiendishly difficult #mathartchallenge

sketch_2020_03_30z.pyde

"""
Annie Perkins Math Art Challenge
https://twitter.com/anniek_p/status/1244220881347502080
Peter Farrell
https://github.com/hackingmath/pygame_sketches/blob/master/binary_grid_challenge.py
Alexandre Villares
https://gist.github.com/villares/219b457c82adfd73b6664aa10cb681f2
"""

from random import choice, randint

# define constants
BLACK = (0, 0, 0)
CYAN = (0, 255, 255)

def setup():
    global len_line, offset1_list, offset2_list
    size(600, 600)
    len_line = width / rows
    rows, cols = 30, 30
    offset1_list = [choice([0, 1]) for i in range(rows)]
    offset2_list = [choice([0, 1]) for i in range(cols)]
    print(offset1_list)
    print(offset2_list)
    
def draw_lines_row(y, offset):
    """draws lines every other square"""
    for c in range(0, cols, 2):
        line(len_line * (c + offset), y, len_line * (c + 1 + offset), y)

def draw_lines_col(x, offset):
    """draws lines every other square"""
    for r in range(0, rows, 2):
        line(x, len_line * (r + offset), x, len_line * (r + 1 + offset))

def draw():
    # fill the screen with background color
    background(*CYAN)

    idx = randint(0, rows - 1)
    if frameCount % 6 == 0:
        offset1_list[idx] = 1 - offset1_list[idx]
    if frameCount % 6 == 3:
        offset2_list[idx] = 1 - offset2_list[idx]

    for r in range(rows):
        for c in range(cols):
            draw_lines_row(c*len_line, offset1_list[c])
            draw_lines_col(r*len_line, offset2_list[r])