Pygame Events: event.get() and Event Types

Pygame records everything the player does as an event: a key going down, the mouse moving, the window's close button. The events wait in a queue, and pygame.event.get() hands you all of them once per frame:

for event in pygame.event.get():
    if event.type == pygame.QUIT:
        running = False

Each event has a type and, depending on the type, some attributes. This program prints every key, click and wheel turn it receives:

import pygame

pygame.init()
screen = pygame.display.set_mode((480, 300))
clock = pygame.time.Clock()
font = pygame.font.Font(None, 30)
last = "Press a key or click"
running = True

while running:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False
        elif event.type == pygame.KEYDOWN:
            last = f"KEYDOWN {pygame.key.name(event.key)}"
            print(last)
        elif event.type == pygame.KEYUP:
            print(f"KEYUP {pygame.key.name(event.key)}")
        elif event.type == pygame.MOUSEBUTTONDOWN:
            last = f"MOUSEBUTTONDOWN button {event.button} at {event.pos}"
            print(last)
        elif event.type == pygame.MOUSEWHEEL:
            last = f"MOUSEWHEEL y={event.y}"
            print(last)

    screen.fill((22, 24, 36))
    screen.blit(font.render(last, True, (255, 255, 255)), (20, 130))
    pygame.display.flip()
    clock.tick(60)

pygame.quit()

Press Play, click the game, then press keys and click. The Console shows each event.

Common event types

Key events are covered on keyboard input and mouse events on mouse input.

Events or state?

Events tell you that something changed: a key went down once. For things that last, such as holding an arrow key to walk, ask for the current state instead: pygame.key.get_pressed() and pygame.mouse.get_pressed(). A rule of thumb:

• One action per press (jump, shoot, pause, menu choice): use the KEYDOWN event.
• Continuous action while held (walk, aim, accelerate): use get_pressed().

Read the queue once per frame

pygame.event.get() empties the queue. A second call in the same frame gets nothing that the first one took, so a game that calls it in two places loses key presses at random. Read events in one loop and pass what you need along.

The queue also needs reading for the window to stay alive: if your loop never calls pygame.event.get(), the system reports the window as not responding.

Custom events

Your own events go through the same queue. pygame.event.custom_type() returns a fresh event type number, and pygame.event.post() puts an event in the queue:

import pygame

pygame.init()
screen = pygame.display.set_mode((480, 300))
clock = pygame.time.Clock()
font = pygame.font.Font(None, 36)

SCORED = pygame.event.custom_type()
score = 0
running = True

while running:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False
        elif event.type == pygame.KEYDOWN and event.key == pygame.K_SPACE:
            pygame.event.post(pygame.event.Event(SCORED, points=10))
        elif event.type == SCORED:
            score += event.points
            print("scored", event.points)

    screen.fill((22, 24, 36))
    screen.blit(font.render(f"Score: {score}  (press Space)", True, "white"), (20, 130))
    pygame.display.flip()
    clock.tick(60)

pygame.quit()

Any keyword you pass to pygame.event.Event (here points) becomes an attribute of the event. Custom events are a clean way for one part of a game to tell another that something happened. To post one on a timer, see pygame timers.

Other event functions