WindowResizing

import pygame
from pygame.locals import *
pygame.init()
screen=pygame.display.set_mode((500,500),HWSURFACE|DOUBLEBUF|RESIZABLE)
pic=pygame.image.load("example.png") #You need an example picture in the same folder as this file!
screen.blit(pygame.transform.scale(pic,(500,500)),(0,0))
pygame.display.flip()
while True:
    pygame.event.pump()
    event=pygame.event.wait()
    if event.type==QUIT: pygame.display.quit()
    elif event.type==VIDEORESIZE:
        screen=pygame.display.set_mode(event.dict['size'],HWSURFACE|DOUBLEBUF|RESIZABLE)
        screen.blit(pygame.transform.scale(pic,event.dict['size']),(0,0))
        pygame.display.flip()