title: How to make the PyGame window open in full-screen mode
body: <p>I'm working with <code>pygame</code> to make an alien shooter game. I want to make the game window adapt to the user's screen size so that it automatically starts in full-screen mode, by detecting their screen size. I'm thinking of using <code>pygame.display.set_mode((screen_width, screen_height))</code>, but I don't know how to make Python detect the user's screen size. How do I do that?</p>