Simple turtle program to draw 2d polygons of any size

draw_polygons.py

__author__ = "@kaizen86"
import turtle

def draw_polygon(sides, size):
    if sides < 3:
        # Stop here with an error
        raise Exception("A polygon must have at least 3 sides")
    step = size/sides # Reduce length of each side with higher side counts
    for i in range(sides):
        turtle.forward(step) # Draw side
        turtle.right(360/sides) # Compute angle between sides
    turtle.forward(step) # Final step doesn't need to be followed by a turn

# Allow the file to be imported as well as directly run
if __name__ == '__main__':
    turtle.clear()
    for i in range(3, 10):
        # Prepare for shape draw
        turtle.penup()
        turtle.setheading(0) # Ensure same starting direction
        turtle.goto(i*80-500, 0) # Move across the screen left to right
        turtle.pendown()
        # Do the thing
        draw_polygon(i, 200)

    input("Done")