How do I create a checker board pattern?

I am trying to write a code that can generate an checker board pattern. The final image size should be 100 x 100, the checker board size 5 x 5, such that each box has dimensions h/5 and w/5. The code I have is wrong:

from PIL import Image, ImageDraw

h = 500
w = 500
img = Image.new("RGB", (h,w), (255, 0, 0))   # create a new 15x15 image
pixels = img.load()                          # create the pixel map
print("1")

for i in range (h):
    for j in range(w):
        if ((i + j)%2) != 0:
            im = Image.new('RGB', (h//5, w//5), 'black')
        else:
            draw = ImageDraw.Draw(img, "RGBA")
            draw.rectangle(((h//5, w//5), (i+.5, j+.5)), fill="blue")
    
print ("done")
img.show()

Answer

I know it’s already been answered, here’s a way to loop over it differently

from PIL import Image

h = 500
w = 500

# You can also easily set the number of squares per row
number_of_square_across = 10

# You can also easily set the colors
color_one = (0, 0, 0)
color_two = (0, 0, 255)

length_of_square = h/number_of_square_across
length_of_two_squares = h/number_of_square_across*2

img = Image.new("RGB", (h, w), (255, 0, 0))  # create a new 15x15 image
pixels = img.load()  # create the pixel map

for i in range(h):
    # for every 100 pixels out of the total 500 
    # if its the first 50 pixels
    if (i % length_of_two_squares) >= length_of_square:
        for j in range(w):
            if (j % length_of_two_squares) < length_of_square:
                pixels[i,j] = color_one
            else:
                pixels[i,j] = color_two

    # else its the second 50 pixels         
    else:
        for j in range(w):
            if (j % length_of_two_squares) >= length_of_square:
                pixels[i,j] = color_one
            else:
                pixels[i,j] = color_two

print("done")
img.show()