My Pygame Code always says "(Not responding")

[Windspar]

My code was just a rough draft.
In game programming. It better to have one main loop. You will learn to interface with main loop.

You were to fill in the blanks.
Here full working code.

import pygame

def main():
    pygame.init()
    pygame.display.set_caption("Example")
    surface = pygame.display.set_mode((700, 600))
    clock = pygame.time.Clock()
    delta = 0
    fps = 60

    glow = True
    glow_color = pygame.Color('white')
    glow_interval_on = 3000
    glow_interval_off = 300
    glow_ticks = glow_interval_on
    spotlight = pygame.Rect(0, 0, 20, 20)
    spotlight_position = pygame.Vector2(spotlight.center)
    background_color = pygame.Color('black')
    velocity = 0.08

    running = True
    # Main loop
    while running:
        # Event loop
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                running = False

        # Logic
        ticks = pygame.time.get_ticks()
        if ticks > glow_ticks:
            glow = not glow
            if glow:
                glow_ticks += glow_interval_on
                glow_color = pygame.Color('white')
            else:
                glow_ticks += glow_interval_off
                glow_color = pygame.Color('black')

        keys_pressed = pygame.key.get_pressed()
        if keys_pressed[pygame.K_UP] or keys_pressed[pygame.K_w]:
            spotlight_position.y -= velocity * delta

        if keys_pressed[pygame.K_DOWN] or keys_pressed[pygame.K_s]:
            spotlight_position.y += velocity * delta

        if keys_pressed[pygame.K_LEFT] or keys_pressed[pygame.K_a]:
            spotlight_position.x -= velocity * delta

        if keys_pressed[pygame.K_RIGHT] or keys_pressed[pygame.K_d]:
            spotlight_position.x += velocity * delta

        spotlight.center = spotlight_position

        # Draw
        surface.fill(background_color)
        surface.fill(glow_color, spotlight)

        pygame.display.update()

        # Idle
        delta = clock.tick(fps)

main()