How To Get Keyboard Input In Pygame

Question

I am trying to get keyboard input on a program where the user has to move a dot around the screen. However when I run the program, the console does not come up. Could you please help me fix this error? Here is my code:

import pygame
import random
pygame.init()
x=0
y=0
xdir=5
ydir=5
r = random.randint(10,255)
g = random.randint(10,255)
b = random.randint(10,255)
screen = pygame.display.set_mode((500,300))
pygame.draw.circle(screen, (r, g, b), (x,y), 15, 0)
USI = pygame.key.get_pressed()
while True:
    pygame.draw.circle(screen, (r, g, b), (x,y), 15, 0)
    pygame.display.update()
    if USI[pygame.K_LEFT]:
        x -= 5
if USI[pygame.K_RIGHT]:
    x += 5
if USI[pygame.K_UP]:
    y -= 5
if USI[pygame.K_DOWN]:
    y += 5

score 1 · Answer 1 · answered Mar 30 '22 at 06:21

a sample loop to deteck key pressed with pygame:

# creating a running loop
while True:
       
    # creating a loop to check events that
    # are occuring
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            pygame.quit()
            sys.exit()
         
        # checking if keydown event happened or not
        if event.type == pygame.KEYDOWN:
               
            # checking if key "A" was pressed
            if event.key == pygame.K_a:
                print("Key A has been pressed")
               
            # checking if key "J" was pressed
            if event.key == pygame.K_j:
                print("Key J has been pressed")
               
            # checking if key "P" was pressed
            if event.key == pygame.K_p:
                print("Key P has been pressed")
             
            # checking if key "M" was pressed
            if event.key == pygame.K_m:
                print("Key M has been pressed")

score 1 · Answer 2 · answered Mar 30 '22 at 06:30

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()

https://replit.com/@Rabbid76/PyGame-ContinuousMovement#main.py

this should help you figure out movement in pygame.

score 0 · Answer 3 · answered Mar 30 '22 at 06:28

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)

How To Get Keyboard Input In Pygame

3 Answers3