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pygame.display.update(); pygame.error: video system not initialized [duplicate]

This question already has answers here:
pygame.error: video system not initialized
(5 answers)
why is the exit window button work but the exit button in the game does not work?
(1 answer)
Closed 1 year ago.
Here is my underdeveloped pygame ping-pong game, but my sprites(player&opponent) ain't moving, on giving a keyboard input. And when I quit the program, it yells an error pygame.error: video system not initialized. My pygame is the latest 1.9.6 version with all the files up-to-daee. However, I am certain that pygame.display is generating this error, but I even tried pygame.display.init() and that too didn't worked :(
import pygame
# Initialization
pygame.init()
# Screen, Caption and Icon
width = 800
height = 600
screen = pygame.display.set_mode((width, height))
pygame.display.set_caption('PyGame')
icon = pygame.image.load('ping-pong.png')
pygame.display.set_icon(icon)
# Create Rects
player = pygame.Rect((5, 230), (10, 120))
opponent = pygame.Rect((785, 230), (10, 120))
# Game Variables
playerY_change = 0
opponentY_change = 0
game_over = False
while not game_over:
# Coloring the Screen
screen.fill((27, 35, 43))
# Draw Rects
pygame.draw.rect(screen, (255,255,255), player)
pygame.draw.rect(screen, (255,255,255), opponent)
# Managing Events
for event in pygame.event.get():
if event.type == pygame.QUIT:
game_over = True
pygame.quit()
if event.type == pygame.KEYUP:
if event.type == pygame.K_UP:
opponentY_change -= 3
if event.type == pygame.K_DOWN:
opponentY_change += 3
if event.type == pygame.K_w:
playerY_change -= 3
if event.type == pygame.K_s:
playerY_change += 3
if event.type == pygame.KEYDOWN:
if (event.type == pygame.K_UP) or (event.type == pygame.K_DOWN):
opponentY_change = 0
if (event.type == pygame.K_w) or (event.type == pygame.K_s):
playerY_change = 0
# Moving my sprites
player.y += playerY_change
opponent.y += opponentY_change
# Updating the screen on every iter of loop
pygame.display.update()

Here, you have two different problems :
First the movement is not working because to differentiate the keys, you use event.type to compare where it should be event.key. Try with for example :
if event.key == pygame.K_UP:
opponentY_change -= 3
The other problem is that when the game is over, you use pygame.quit() but later on the loop, you use pygame.display.update(). You should put the display update at the beginning of the loop.

Player not moving in pygame [duplicate]

This question already has answers here:
How to get keyboard input in pygame?
(11 answers)
How can I make a sprite move when key is held down
(6 answers)
Closed 2 years ago.
I created a program with pygame. The background and player are appearing but the player is not moving. The program is not giving any errors, can you help me? I am using python 3.8.6. Here is some of my code.
# Game Loop
running = True
while running:
for event in pygame.event.get():
player(playerX, playerY)
pygame.display.update()
# Movment
if event.type == pygame.KEYDOWN:
if event.key == pygame.K_a:
player_x_change -= 10
if event.key == pygame.K_d:
player_x_change += 10
if event.key == pygame.K_w:
player_y_change -= 10
if event.key == pygame.K_s:
player_y_change += 10
if event.type == pygame.KEYUP:
if event.key == pygame.K_a:
player_x_change = 0
if event.key == pygame.K_d:
player_x_change = 0
# Close the game
if event.type == pygame.QUIT:
running = False

Your code is just displaying the player, not moving him.
To move the player, you have, in a first step, to define a speed variable. Then you have to get the rectangle of your player. That will allow you to modify player position by using the speed variable you defined.
Also, if you want to move your player, you have to draw the background before drawing the player. Otherwise, every player you draw will not disappear.
And don't forget to define the game speed.
Code
#!/usr/bin/python3
import pygame
# set the game speed
delay = 10
screen = pygame.display.set_mode((800, 600))
# loading player image and get pos
player = pygame.image.load('pixel_ship_yellow.png')
player_pos = player.get_rect()
# define speed variable
speed = [1, 1]
while True:
for event in pygame.event.get():
if event.type == pygame.QUIT:
break
# drawing background
screen.fill((0,0,0))
# apply speed (position is automatically updated)
player_pos = player_pos.move(speed)
# drawing player
screen.blit(player, player_pos)
pygame.display.flip()
# set the game speed
pygame.time.delay(delay)

You need to check for the event when a user pressed a button to move the character and then update the players position. For example, here's checking if the player pressed the right arrow:
while running:
for event in pygame.event.get():
player(playerX, playerY)
pygame.display.update()
# checking if right arrow is being pressed
if events.type == pygame.KEYDOWN:
if events.key == pygame.K_RIGHT
# update players x position here to move right
# for example, player.x += 2
# Close the game
if event.type == pygame.QUIT:
running = False

pygame moving left and right issue

I have started making something on pygame but I have encountered an issue when moving left or right. if I quickly change from pressing the right arrow key to pressing the left one and also let go of the right one the block just stops moving. this is my code
bg = "sky.jpg"
ms = "ms.png"
import pygame, sys
from pygame.locals import *
x,y = 0,0
movex,movey=0,0
pygame.init()
screen=pygame.display.set_mode((664,385),0,32)
background=pygame.image.load(bg).convert()
mouse_c=pygame.image.load(ms).convert_alpha()
m = 0
pygame.event.pump()
while 1:
for event in pygame.event.get():
if event.type == QUIT:
pygame.quit()
sys.exit()
if event.type==KEYDOWN:
if event.key==K_LEFT:
movex =-0.5
m = m + 1
if event.key==K_RIGHT:
movex=+0.5
m = m + 1
elif event.type == KEYUP:
if event.key==K_LEFT and not event.key==K_RIGHT:
movex = 0
if event.key==K_RIGHT and not event.key==K_LEFT:
movex =0
x+=movex
y=200
screen.blit(background, (0,0))
screen.blit(mouse_c,(x,y))
pygame.display.update()
is there a way I can change this so if the right arrow key is pressed and the left arrow key is released that it will go right instead of stopping?
P.S
I am still learning pygame and am very new to the module. I'm sorry if this seems like a stupid question but i couldn't find any answers to it.

Your problem is that when you test the KEYDOWN events with
if event.key==K_LEFT and not event.key==K_RIGHT:
you always get True, because when event.key==K_LEFT is True,
it also always is not event.key==K_RIGHT (because the key of the event is K_LEFT after all).
My approach to this kind of problem is to separate
the intent from the action. So, for the key
events, I would simply keep track of what action
is supposed to happen, like this:
moveLeft = False
moveRight = False
while True:
for event in pygame.event.get():
if event.type == QUIT:
pygame.quit()
sys.exit()
if event.type == KEYDOWN:
if event.key == K_LEFT: moveLeft = True
if event.key == K_RIGHT: moveRight = True
elif event.type == KEYUP:
if event.key == K_LEFT: moveLeft = False
if event.key == K_RIGHT: moveRight = False
Then, in the "main" part of the loop, you can
take action based on the input, such as:
while True:
for event in pygame.event.get():
...
if moveLeft : x -= 0.5
if moveRight : x += 0.5

the problem is that you have overlapping key features; If you hold down first right and then left xmove is first set to 1 and then changes to -1. But then you release one of the keys and it resets xmove to 0 even though you are still holding the other key. What you want to do is create booleans for each key. Here is an example:
demo.py:
import pygame
window = pygame.display.set_mode((800, 600))
rightPressed = False
leftPressed = False
white = 255, 255, 255
black = 0, 0, 0
x = 250
xmove = 0
while True:
window.fill(white)
pygame.draw.rect(window, black, (x, 300, 100, 100))
for event in pygame.event.get():
if event.type == pygame.KEYDOWN:
if event.key == pygame.K_RIGHT:
rightPressed = True
if event.key == pygame.K_LEFT:
leftPressed = True
if event.type == pygame.KEYUP:
if event.key == pygame.K_RIGHT:
rightPressed = False
if event.key == pygame.K_LEFT:
leftPressed = False
xmove = 0
if rightPressed:
xmove = 1
if leftPressed:
xmove = -1
x += xmove
pygame.display.flip()

One way could be to create a queue that keeps track of the button that was pressed last. If we press the right arrow key we'll put the velocity first in the list, and if we then press the left arrow key we put the new velocity first in the list. So the button that was pressed last will always be first in the list. Then we just remove the button from the list when we release it.
import pygame
pygame.init()
screen = pygame.display.set_mode((720, 480))
clock = pygame.time.Clock()
FPS = 30
rect = pygame.Rect((350, 220), (32, 32)) # Often used to track the position of an object in pygame.
image = pygame.Surface((32, 32)) # Images are Surfaces, so here I create an 'image' from scratch since I don't have your image.
image.fill(pygame.Color('white')) # I fill the image with a white color.
velocity = [0, 0] # This is the current velocity.
speed = 200 # This is the speed the player will move in (pixels per second).
dx = [] # This will be our queue. It'll keep track of the horizontal movement.
while True:
dt = clock.tick(FPS) / 1000.0 # This will give me the time in seconds between each loop.
for event in pygame.event.get():
if event.type == pygame.QUIT:
raise SystemExit
elif event.type == pygame.KEYDOWN:
if event.key == pygame.K_LEFT:
dx.insert(0, -speed)
elif event.key == pygame.K_RIGHT:
dx.insert(0, speed)
elif event.type == pygame.KEYUP:
if event.key == pygame.K_LEFT:
dx.remove(-speed)
elif event.key == pygame.K_RIGHT:
dx.remove(speed)
if dx: # If there are elements in the list.
rect.x += dx[0] * dt
screen.fill((0, 0, 0))
screen.blit(image, rect)
pygame.display.update()
# print dx # Uncomment to see what's happening.
You should of course put everything in neat functions and maybe create a Player class.

I know my answer is pretty late but im new to Pygame to and for beginner like me doing code like some previous answer is easy to understand but i have a solution to.I didn`t use the keydown line code, instead i just put the moving event code nested in the main game while loop, im bad at english so i give you guy an example code.
enter code here
while run:
clock.tick(60)
for event in pygame.event.get():
if event.type == pygame.QUIT or event.type == pygame.K_ESCAPE:
run = False
win.blit(bg, (0, 0))
pressed = pygame.key.get_pressed()
if pressed[pygame.K_LEFT]:
x -= 5
if pressed[pygame.K_RIGHT]:
x += 5
if pressed[pygame.K_UP]:
y -= 5
if pressed[pygame.K_DOWN]:
y += 5
win.blit(image,(x,y))
pygame.display.update()
pygame.quit()
This will make the image move rapidly without repeating pushing the key, at long the code just in the main while loop with out inside any other loop.

Why is my ship not shooting bullets?

I have made a game using Python and Pygame. My ship moves around but I am having trouble making it shoot bullets. I have defined a function called shootBullets() but it is not working. And now, if I press the space bar, my ship moves. It is only supposed to move when I press the left or right arrow keys. I want my ship to shoot bullets towards the bottom of the screen when I press the space bar. here is my code:
import pygame,sys
from pygame.locals import *
pygame.init()
black = (0,0,0)
white = (255,255,255)
red = (255,0,0)
green = (0,255,0)
blue = (0,0,255)
bright_blue = (0, 135, 255)
yellow = (255,242,0)
ship_body = (33, 117, 243)
screen = pygame.display.set_mode((500,500))
pygame.display.set_caption("Battleship")
gameExit = False
background = pygame.image.load("Sky Background.png")
bulletImg = pygame.image.load("Bullet.png")
bulletY = 80
def shootBullets():
for event in pygame.event.get():
if event.type == KEYDOWN and event.key == K_SPACE:
bulletY += 5
screen.blit(bulletImg,(247,bulletY))
pygame.key.set_repeat(50,50)
ship_points = [ [100, 50], [180, 95], [320, 95], [400, 50], [250, 35] ]
x = 0
y = 0
while not gameExit:
for event in pygame.event.get():
if event.type == QUIT:
gameExit = True
if event.type == KEYDOWN:
if event.key == pygame.K_LEFT: x = -5
if event.key == pygame.K_RIGHT: x = 5
for point in ship_points:
point[0] += x
for point in ship_points:
if point[0] <= 0 or point[0] >= 500:
gameExit = True
shootBullets()
screen.fill(black)
screen.blit(background, (0,0))
ship = [
pygame.draw.polygon(screen, ship_body, ship_points),
pygame.draw.polygon(screen, black, ship_points, 1)]
pygame.display.update()
pygame.quit()
quit()

In your main loop you are only checking for left and right, not for space. You check in the function shootBullets whether space is pressed, but that is too late, shootBullets will never be executes (actually it will get executed if the for event in get() loop is somehow exited but that is not what you want).
Instead do something like:
while not gameExit:
for event in pygame.event.get():
if event.type == QUIT:
gameExit = True
if event.type == KEYDOWN:
if event.key == pygame.K_LEFT:
move_left()
if event.key == pygame.K_RIGHT:
move_right()
if event.key == pygame.SPACE:
shootBullet()
[...]

New to pygame, drew a rectangle, why can't I move it?

This is my code:
import pygame, sys
from pygame.locals import *
pygame.init()
window = pygame.display.set_mode((800, 600))
pygame.display.set_caption('window')
black = (0,0,0)
white = (255, 255, 255)
logo = pygame.image.load('logo.png').convert_alpha()
clock = pygame.time.Clock()
# Sprites
m1 = pygame.image.load('m1.png').convert_alpha()
m2 = pygame.image.load('m2.png').convert_alpha()
mci = 1
x, y = 0, 0
run = True
while run:
for event in pygame.event.get():
if event.type == QUIT:
pygame.quit()
sys.exit()
if event.type == pygame.KEYDOWN:
if event.type == pygame.K_LEFT:
x -= 10
if event.type == pygame.K_RIGHT:
x += 10
if event.type == pygame.K_UP:
y -= 10
if event.type == pygame.K_DOWN:
y += 10
window.fill(white)
pygame.draw.rect(window, black,(x,y, 50, 50))
pygame.display.flip()
clock.tick(10)
Everything shows up, but I can't move the rectangle with my arrow keys, and I always get an error after I quit out of it, help.. Thanks in advance!
P.S I'm obviously copying from a tutorial, but i'm not sure what I've done wrong?

As you worked out, you need to use event.key == .... You probably also want to watch the nesting of your loop, currently you have:
while running:
for event in list_of_events:
process_event
draw_to_screen
wait_a_while
This caused a problem in another question (https://stackoverflow.com/a/13866804/2372604). What you probably want is something more like:
while running:
for event in list_of_events:
process_event
draw_to_screen
wait_a_while
You might also want to change pygame.quit(); sys.exit() to run = false and then add pygame.quit() at the end of the program.

The mistake what I wrote event.type instead of event.key.