Great question! Let's unpack what's happening here—both of your code examples reveal key details about how Pygame and operating systems handle window management.

First, let's clear up a problem with your first code snippet: putting Pygame initialization and window creation inside the infinite while True loop is actually a bad practice. Every loop iteration re-runs pygame.init(), creates a brand new window, and reloads the icon/caption. This wastes system resources, can cause the window to flicker uncontrollably, and might even lead to crashes over time. It only "works" in the sense that the window stays visible, but it's not a valid way to structure a Pygame app.

Now, onto your actual question: why does the second snippet keep the window open? Here's the breakdown:

• When you call pygame.display.set_mode((800, 600)), you're asking your operating system to create a window and link it to your running Python process.
• The window's existence is tied to your process's lifecycle. As long as your process is active (which it is, thanks to the infinite while True: pass loop), the OS won't automatically destroy the window.
• That said, this window is essentially unresponsive. Try clicking the close button or dragging the window—nothing will happen. Pygame relies on you processing its event queue in the loop (with code like for event in pygame.event.get():) to handle user input and system signals. Without this step, the OS will mark your app as "not responding," even though the window remains visible.

The Proper Pygame Loop Structure #

For reference, here's how you should structure a functional, responsive Pygame loop:

import pygame

# Initialize once, outside the loop
pygame.init()
screen = pygame.display.set_mode((800, 600))
pygame.display.set_caption("RPS Pro")
icon = pygame.image.load('icon.png')
pygame.display.set_icon(icon)

# Game loop
running = True
while running:
    # Handle events (critical for responsiveness)
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False
    
    # Update game state, draw graphics, etc.
    
    # Refresh the display
    pygame.display.update()

# Cleanup when the loop ends
pygame.quit()

This structure keeps the window responsive, avoids wasting resources on repeated initialization, and lets the window close properly when you click the close button.

内容的提问来源于stack exchange，提问作者tryingtobeastoic