Do it now!

import math
import pygame


def init_game():
    pygame.init()
    pygame.key.set_repeat(0)
    canvas = pygame.display.set_mode((800, 600))
    fps_clock = pygame.time.Clock()
    return canvas, fps_clock


def main():
    canvas, fps_clock = init_game()

    title = 'Cardioid'
    pygame.display.set_caption(title)
    max_dots = 300

    while True:
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                pygame.quit()
                return

        draw_cardioid(canvas, max_dots)
        pygame.display.update()
        fps_clock.tick(30)


def draw_cardioid(canvas, max_dots):

    canvas.fill((0, 0, 0))
    start_x = canvas.get_width() // 2
    start_y = canvas.get_height() // 2
    radius = 250

    for i in range(max_dots):
        radian = (math.pi / 180) * (360 / max_dots) * i
        sx = start_x + int(math.cos(radian) * radius)
        sy = start_y + int(math.sin(radian) * radius)

        ex = start_x + int(math.cos(radian * 2) * radius)
        ey = start_y + int(math.sin(radian * 2) * radius)

        pygame.draw.line(canvas, (0, 255, 0), (sx, sy), (ex, ey))


if __name__ == '__main__':
    main()