import pygame
import sys
pygame.init

display = pygame.display.set_mode((300, 300))
display.fill((255, 255, 255))

pygame.draw.rect(display, 0, 0, 255),
(40, 80, 200, 80, (width=0, border_radius=20))

while True :
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            pygame.quit()
            sys.exit()
    pygame.display.update()