How to get keyboard input in pygame?

pygame.key.get_pressed() returns a list with the state of each key. If a key is held down, the state for the key is 1, otherwise 0. Use pygame.key.get_pressed() to evaluate the current state of a button and get continuous movement:

while True:

    keys = pygame.key.get_pressed()
    if keys[pygame.K_LEFT]:
        x -= speed
    if keys[pygame.K_RIGHT]:
        x += speed
    if keys[pygame.K_UP]:
        y -= speed
    if keys[pygame.K_DOWN]:
        y += speed

This code can be simplified by subtracting "left" from "right" and "up" from "down":

while True:

    keys = pygame.key.get_pressed()
    x += (keys[pygame.K_RIGHT] - keys[pygame.K_LEFT]) * speed
    y += (keys[pygame.K_DOWN] - keys[pygame.K_UP]) * speed

The keyboard events (see pygame.event module) occur only once when the state of a key changes. The KEYDOWN event occurs once every time a key is pressed. KEYUP occurs once every time a key is released. Use the keyboard events for a single action or movement:

while True:

    for event in pygame.event.get():
        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_LEFT:
                x -= speed
            if event.key == pygame.K_RIGHT:
                x += speed
            if event.key == pygame.K_UP:
                y -= speed
            if event.key == pygame.K_DOWN:
                y += speed

See also Key and Keyboard event

Minimal example of continuous movement: replit.com/@Rabbid76/PyGame-ContinuousMovement

import pygame

pygame.init()
window = pygame.display.set_mode((300, 300))
clock = pygame.time.Clock()

rect = pygame.Rect(0, 0, 20, 20)
rect.center = window.get_rect().center
vel = 5

run = True
while run:
    clock.tick(60)
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            run = False
        if event.type == pygame.KEYDOWN:
            print(pygame.key.name(event.key))

    keys = pygame.key.get_pressed()
    
    rect.x += (keys[pygame.K_RIGHT] - keys[pygame.K_LEFT]) * vel
    rect.y += (keys[pygame.K_DOWN] - keys[pygame.K_UP]) * vel
        
    rect.centerx = rect.centerx % window.get_width()
    rect.centery = rect.centery % window.get_height()

    window.fill(0)
    pygame.draw.rect(window, (255, 0, 0), rect)
    pygame.display.flip()

pygame.quit()
exit()

Minimal example for a single action: replit.com/@Rabbid76/PyGame-ShootBullet

import pygame
pygame.init()

window = pygame.display.set_mode((500, 200))
clock = pygame.time.Clock()

tank_surf = pygame.Surface((60, 40), pygame.SRCALPHA)
pygame.draw.rect(tank_surf, (0, 96, 0), (0, 00, 50, 40))
pygame.draw.rect(tank_surf, (0, 128, 0), (10, 10, 30, 20))
pygame.draw.rect(tank_surf, (32, 32, 96), (20, 16, 40, 8))
tank_rect = tank_surf.get_rect(midleft = (20, window.get_height() // 2))

bullet_surf = pygame.Surface((10, 10), pygame.SRCALPHA)
pygame.draw.circle(bullet_surf, (64, 64, 62), bullet_surf.get_rect().center, bullet_surf.get_width() // 2)
bullet_list = []

run = True
while run:
    clock.tick(60)
    current_time = pygame.time.get_ticks()
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            run = False

        if event.type == pygame.KEYDOWN:
            bullet_list.insert(0, tank_rect.midright)

    for i, bullet_pos in enumerate(bullet_list):
        bullet_list[i] = bullet_pos[0] + 5, bullet_pos[1]
        if bullet_surf.get_rect(center = bullet_pos).left > window.get_width():
            del bullet_list[i:]
            break

    window.fill((224, 192, 160))
    window.blit(tank_surf, tank_rect)
    for bullet_pos in bullet_list:
        window.blit(bullet_surf, bullet_surf.get_rect(center = bullet_pos))
    pygame.display.flip()

pygame.quit()
exit()

You can get the events from pygame and then watch out for the KEYDOWN event, instead of looking at the keys returned by get_pressed()(which gives you keys that are currently pressed down, whereas the KEYDOWN event shows you which keys were pressed down on that frame).

What's happening with your code right now is that if your game is rendering at 30fps, and you hold down the left arrow key for half a second, you're updating the location 15 times.

events = pygame.event.get()
for event in events:
    if event.type == pygame.KEYDOWN:
        if event.key == pygame.K_LEFT:
            location -= 1
        if event.key == pygame.K_RIGHT:
            location += 1

To support continuous movement while a key is being held down, you would have to establish some sort of limitation, either based on a forced maximum frame rate of the game loop or by a counter which only allows you to move every so many ticks of the loop.

move_ticker = 0
keys=pygame.key.get_pressed()
if keys[K_LEFT]:
    if move_ticker == 0:
        move_ticker = 10
        location -= 1
        if location == -1:
            location = 0
if keys[K_RIGHT]:
    if move_ticker == 0:   
        move_ticker = 10     
        location+=1
        if location == 5:
            location = 4

Then somewhere during the game loop you would do something like this:

if move_ticker > 0:
    move_ticker -= 1

This would only let you move once every 10 frames (so if you move, the ticker gets set to 10, and after 10 frames it will allow you to move again)

Tags:

Keyboard

Pygame

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