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How to move the Rocket in my first project on pygame Python

I'll much appreciate it if you help me to resolve the issue with moving Rocket in my project.
I've started to code my first game, based on material that I've learned in the "Python crash course" book.
I need to make Rocket in the game to move all over the window and around its axis.
Everything worked (moving left, right, top, bottom), then I decided to make my Rocket to move around its axis. I spend a lot of time to know how to do it and it already works (left Shift).
But now I faced another problem. My Rocket now doesn't move on the screen, only around its axis. I understand that my question may seem very stupid, and somewhere in my code is obviously a lack of simple logic. But I tried to fix it by myself for several hours and didn't get a result.
Here is my code:
import pygame
import sys
class Settings():
"""A class to store all settings for Rocket."""
def __init__(self):
"""Initialize the game screen settings."""
# Screen settings.
self.screen_width = 900
self.screen_height = 700
self.bg_color = (21, 36, 110)
class Rocket():
"""A class that describes rocket."""
def __init__(self, screen):
"""Initialize rocket and its starting position."""
self.screen = screen
#Load the rocket image and get its rect.
self.image = pygame.image.load('/media/philip/9074-45DF/Python/rocket/images/rocket.png')
self.rect = self.image.get_rect()
self.screen_rect = screen.get_rect()
#set starting position of a rocket.
self.rect.centerx = self.screen_rect.centerx
self.rect.centery = self.screen_rect.centery
#movement flag.
self.moving_right = False
self.moving_left = False
self.moving_up = False
self.moving_down = False
self.rotate_left = False
self.rocket_angle = 0
def update(self):
"""Update the rocket position based on the movement flag."""
if self.moving_right and self.rect.right < self.screen_rect.right:
self.rect.centerx += 2
if self.moving_left and self.rect.left > 0:
self.rect.centerx -= 2
if self.moving_up and self.rect.top > 0:
self.rect.centery -= 2
if self.moving_down and self.rect.bottom < self.screen_rect.bottom:
self.rect.centery += 2
def rotated_center(self, image, rocket_angle):
"""Rotating rocket around its axis."""
self.center = self.image.get_rect().center
self.rotated_image = pygame.transform.rotate(self.image, self.rocket_angle)
self.new_rect = self.rotated_image.get_rect(center = self.center)
return self.rotated_image, self.new_rect
def blit_rocket(self, rect, rocket_angle):
"""Draw the rocket at its current location."""
if self.rotate_left:
self.rocket_angle = (self.rocket_angle + 1) % 360
self.screen.blit(self.rotated_image, self.new_rect)
else:
self.rocket_angle = (self.rocket_angle + 0) % 360
self.screen.blit(self.rotated_image, self.new_rect)
def check_events(self):
"""Respond to a key events."""
# Responses to the keydown events.
if event.type == pygame.KEYDOWN:
if event.key == pygame.K_RIGHT:
self.moving_right = True
if event.key == pygame.K_LEFT:
self.moving_left = True
if event.key == pygame.K_DOWN:
self.moving_down = True
if event.key == pygame.K_UP:
self.moving_up = True
if event.key == pygame.K_LSHIFT:
self.rotate_left = True
# Responses to the keyup events.
if event.type == pygame.KEYUP:
if event.key == pygame.K_RIGHT:
self.moving_right = False
if event.key == pygame.K_LEFT:
self.moving_left = False
if event.key == pygame.K_DOWN:
self.moving_down = False
if event.key == pygame.K_UP:
self.moving_up = False
if event.key == pygame.K_LSHIFT:
self.rotate_left = False
pygame.init()
rocket_settings = Settings()
icon = pygame.image.load('/media/philip/9074-45DF/Python/rocket/images/rocket_icon.png')
pygame.display.set_icon(icon)
screen = pygame.display.set_mode((rocket_settings.screen_width, rocket_settings.screen_height))
pygame.display.set_caption("Rocket")
rocket = Rocket(screen)
"""The main game loop."""
while True:
for event in pygame.event.get():
if event.type == pygame.QUIT:
sys.exit()
screen.fill((rocket_settings.bg_color))
rocket.update()
rocket.check_events()
rocket.rotated_center(rocket.image, rocket.rocket_angle)
rocket.blit_rocket(rocket.rect,rocket.rocket_angle)
pygame.display.flip()

event has to be an argument of the method Rocket.check_events:
class Rocket():
# [...]
def check_events(self, event): # event argument
"""Respond to a key events."""
# Responses to the keydown events.
# [...]
You have to call rocket.check_events() in the event loop and to pass the event to the method:
while True:
for event in pygame.event.get():
if event.type == pygame.QUIT:
sys.exit()
rocket.check_events(event) # <--- ADD
screen.fill((rocket_settings.bg_color))
rocket.update()
# rocket.check_events() <--- DELETE
rocket.rotated_center(rocket.image, rocket.rocket_angle)
rocket.blit_rocket(rocket.rect,rocket.rocket_angle)
pygame.display.flip()
pygame.Surface.get_rect.get_rect() returns a rectangle with the size of the Surface object, but it returns a rectangle that always starts at (0, 0).
You must get the position of the the object from self.rect.center rather than self.image.get_rect().center:
class Rocket():
# [...]
def rotated_center(self, image, rocket_angle):
"""Rotating rocket around its axis."""
self.rotated_image = pygame.transform.rotate(self.image, self.rocket_angle)
self.new_rect = self.rotated_image.get_rect(center = self.rect.center)
return self.rotated_image, self.new_rect
Complete example:
import pygame
import sys
class Settings():
"""A class to store all settings for Rocket."""
def __init__(self):
"""Initialize the game screen settings."""
# Screen settings.
self.screen_width = 900
self.screen_height = 700
self.bg_color = (21, 36, 110)
class Rocket():
"""A class that describes rocket."""
def __init__(self, screen):
"""Initialize rocket and its starting position."""
self.screen = screen
#Load the rocket image and get its rect.
self.image = pygame.image.load('/media/philip/9074-45DF/Python/rocket/images/rocket.png')
self.rect = self.image.get_rect()
self.screen_rect = screen.get_rect()
#set starting position of a rocket.
self.rect.centerx = self.screen_rect.centerx
self.rect.centery = self.screen_rect.centery
#movement flag.
self.moving_right = False
self.moving_left = False
self.moving_up = False
self.moving_down = False
self.rotate_left = False
self.rocket_angle = 0
def update(self):
"""Update the rocket position based on the movement flag."""
if self.moving_right and self.rect.right < self.screen_rect.right:
self.rect.centerx += 2
if self.moving_left and self.rect.left > 0:
self.rect.centerx -= 2
if self.moving_up and self.rect.top > 0:
self.rect.centery -= 2
if self.moving_down and self.rect.bottom < self.screen_rect.bottom:
self.rect.centery += 2
def rotated_center(self, image, rocket_angle):
"""Rotating rocket around its axis."""
self.rotated_image = pygame.transform.rotate(self.image, self.rocket_angle)
self.new_rect = self.rotated_image.get_rect(center = self.rect.center)
return self.rotated_image, self.new_rect
def blit_rocket(self, rect, rocket_angle):
"""Draw the rocket at its current location."""
if self.rotate_left:
self.rocket_angle = (self.rocket_angle + 1) % 360
self.screen.blit(self.rotated_image, self.new_rect)
else:
self.rocket_angle = (self.rocket_angle + 0) % 360
self.screen.blit(self.rotated_image, self.new_rect)
def check_events(self, event):
"""Respond to a key events."""
# Responses to the keydown events.
if event.type == pygame.KEYDOWN:
if event.key == pygame.K_RIGHT:
self.moving_right = True
if event.key == pygame.K_LEFT:
self.moving_left = True
if event.key == pygame.K_DOWN:
self.moving_down = True
if event.key == pygame.K_UP:
self.moving_up = True
if event.key == pygame.K_LSHIFT:
self.rotate_left = True
# Responses to the keyup events.
if event.type == pygame.KEYUP:
if event.key == pygame.K_RIGHT:
self.moving_right = False
if event.key == pygame.K_LEFT:
self.moving_left = False
if event.key == pygame.K_DOWN:
self.moving_down = False
if event.key == pygame.K_UP:
self.moving_up = False
if event.key == pygame.K_LSHIFT:
self.rotate_left = False
pygame.init()
rocket_settings = Settings()
icon = pygame.image.load('/media/philip/9074-45DF/Python/rocket/images/rocket_icon.png')
pygame.display.set_icon(icon)
screen = pygame.display.set_mode((rocket_settings.screen_width, rocket_settings.screen_height))
pygame.display.set_caption("Rocket")
rocket = Rocket(screen)
"""The main game loop."""
while True:
for event in pygame.event.get():
if event.type == pygame.QUIT:
sys.exit()
rocket.check_events(event)
screen.fill((rocket_settings.bg_color))
rocket.update()
rocket.rotated_center(rocket.image, rocket.rocket_angle)
rocket.blit_rocket(rocket.rect,rocket.rocket_angle)
pygame.display.flip()

I cannot add gravity to my player in pygame [duplicate]

This question already has answers here:
Pygame doesn't let me use float for rect.move, but I need it
(2 answers)
Closed 2 years ago.
I tried adding gravity to my player in pygame, but I can move the player with key controls but gravity is not working, Here I used sprite class for making this. I got the rect of the image then add the x momentum and y momentum. X momentum worked while moving the player but y momentum didn't work while adding the gravity. Please help!
# Platformer
import pygame
# Basic Setup
pygame.init()
clock = pygame.time.Clock()
# Game Colors
white = (255, 255, 255)
light_blue = (105, 142, 255)
# Game Settings
game_title = "Platformer!"
screen_width = 1280
screen_height = 750
fps = 120
player_speed = 4
player_gravity = 0.2
# Main Window
screen = pygame.display.set_mode((screen_width, screen_height))
pygame.display.set_caption(game_title)
class Player(pygame.sprite.Sprite):
def __init__(self):
super().__init__()
self.image = pygame.image.load("IMGs/player.png")
self.image.set_colorkey(white)
self.rect = self.image.get_rect(center=(screen_width / 2, screen_height / 2))
self.x_momentum = 0
self.y_momentum = 0
self.moving_right = False
self.moving_left = False
def move(self):
# Set the movement to zero at first
self.x_momentum = 0
self.y_momentum = 0
# Move the player on key press
if self.moving_right:
self.x_momentum += player_speed
elif self.moving_left:
self.x_momentum -= player_speed
# Add Gravity
self.y_momentum += player_gravity
# Move the player
self.rect.x += self.x_momentum
self.rect.y += self.y_momentum
def update(self):
self.move()
class Main:
def __init__(self):
# Sprites
self.all_sprites = pygame.sprite.Group()
# Player Sprite
self.player = Player()
self.all_sprites.add(self.player)
def draw(self, surface):
self.all_sprites.draw(surface)
def update(self):
self.all_sprites.update()
main_game = Main()
def main_game_loop():
while True:
# Handling Inputs
for event in pygame.event.get():
if event.type == pygame.QUIT:
pygame.quit()
exit(0)
if event.type == pygame.KEYDOWN:
if event.key == pygame.K_RIGHT or event.key == pygame.K_d:
main_game.player.moving_right = True
elif event.key == pygame.K_LEFT or event.key == pygame.K_a:
main_game.player.moving_left = True
if event.type == pygame.KEYUP:
if event.key == pygame.K_RIGHT or event.key == pygame.K_d:
main_game.player.moving_right = False
elif event.key == pygame.K_LEFT or event.key == pygame.K_a:
main_game.player.moving_left = False
# Draw / Render
screen.fill(light_blue)
main_game.draw(screen)
main_game.update()
pygame.display.update()
# Manage Speed
clock.tick(fps)
main_game_loop()

The gravity doesn't work because self.y_momentum is set 0 at the begin of Player.move:
class Player(pygame.sprite.Sprite):
# [...]
def move(self):
# Set the movement to zero at first
self.x_momentum = 0
self.y_momentum = 0
# [...]
Since pygame.Rect is supposed to represent an area on the screen, a pygame.Rect object can only store integral data.
The coordinates for Rect objects are all integers. [...]
The fraction part of the coordinates gets lost when the position stored in the Rect object is decremented:
# Move the player
self.rect.x += self.x_momentum
self.rect.y += self.y_momentum
If you want to store object positions with floating point accuracy, you have to store the location of the object in separate variables respectively attributes and to synchronize the pygame.Rect object. round the coordinates and assign it to the location (e.g. .topleft) of the rectangle:
class Player(pygame.sprite.Sprite):
def __init__(self):
# [...]
self.x = screen_width // 2
self.y = screen_height // 2
self.rect = self.image.get_rect(center = (self.x, self.y))
# [...]
def move(self):
# [...]
# Move the player
self.x += self.x_momentum
self.y += self.y_momentum
self.rect.topleft = round(self.x), round(self.y)

I cant move my sprite unless I shoot first?

I'm developing a basic game, where you can move around and shoot projectiles to kill randomly spawned enemies, but if I boot the game and I try to move before I do anything else, the game crashes. If I shoot a projectile first, however, the game runs perfectly and I can move around without any problems, but I can't seem to figure out why this is.
import pygame
import random
BLACK = (0, 0, 0)
WHITE = (255, 255, 255)
RED = (255, 0, 0)
GREEN = (0, 255, 0)
BLUE = (0, 0, 255)
#Classes
class Player(pygame.sprite.Sprite):
def __init__(self, filename, x, y):
super().__init__()
self.image = pygame.image.load(filename).convert()
self.image.set_colorkey(BLACK)
self.rect = self.image.get_rect()
self.rect.y = y
self.rect.x = x
self.change_x = 0
self.change_y = 0
self.walls = None
def changespeed(self, x, y):
self.change_x += x
self.change_y += y
def update(self):
self.rect.x += self.change_x
block_hit_list = pygame.sprite.spritecollide(self, self.walls, False)
for block in block_hit_list:
if self.change_x > 0:
self.rect.right = block.rect.left
else:
self.rect.left = block.rect.right
self.rect.y += self.change_y
block_hit_list = pygame.sprite.spritecollide(self, self.walls, False)
for block in block_hit_list:
if self.change_y > 0:
self.rect.bottom = block.rect.top
else:
self.rect.top = block.rect.bottom
class Wall(pygame.sprite.Sprite):
def __init__(self, x, y, width, height):
super().__init__()
self.image = pygame.Surface([width, height])
self.image.fill(BLACK)
self.rect = self.image.get_rect()
self.rect.y = y
self.rect.x = x
class Enemy(pygame.sprite.Sprite):
def __init__(self, filename):
super().__init__()
self.image = pygame.image.load(filename).convert()
self.image.set_colorkey(BLACK)
self.rect = self.image.get_rect()
class ProjectileUp(pygame.sprite.Sprite):
def __init__(self, filename):
super().__init__()
self.image = pygame.image.load(filename).convert()
self.image.set_colorkey(BLACK)
self.rect = self.image.get_rect()
def update(self):
self.rect.y -= 5
class ProjectileDown(pygame.sprite.Sprite):
def __init__(self, filename):
super().__init__()
self.image = pygame.image.load(filename).convert()
self.image.set_colorkey(BLACK)
self.rect = self.image.get_rect()
def update(self):
self.rect.y += 5
class ProjectileLeft(pygame.sprite.Sprite):
def __init__(self, filename):
super().__init__()
self.image = pygame.image.load(filename).convert()
self.image.set_colorkey(BLACK)
self.rect = self.image.get_rect()
def update(self):
self.rect.x -= 5
class ProjectileRight(pygame.sprite.Sprite):
def __init__(self, filename):
super().__init__()
self.image = pygame.image.load(filename).convert()
self.image.set_colorkey(BLACK)
self.rect = self.image.get_rect()
def update(self):
self.rect.x += 5
# --- Create the window
#Initialise pygame
pygame.init()
#Window dimensions
screen_width = 1080
screen_height = 607
screen = pygame.display.set_mode([screen_width, screen_height])
#Window display name
pygame.display.set_caption('Labyrinth')
#Sprite Lists
all_sprite_list = pygame.sprite.Group()
block_list = pygame.sprite.Group()
wall_list = pygame.sprite.Group()
projectile_list = pygame.sprite.Group()
#Define game borders
wall = Wall(-32, 0, 10, 607)
wall_list.add(wall)
all_sprite_list.add(wall)
wall = Wall(0 , -64, 1080, 10)
wall_list.add(wall)
all_sprite_list.add(wall)
wall = Wall(1100, 0, 10, 607)
wall_list.add(wall)
all_sprite_list.add(wall)
wall = Wall(0 , 600, 1080, 10)
wall_list.add(wall)
all_sprite_list.add(wall)
#Create player sprite
player = Player("Isaac.png", 420, 150)
all_sprite_list = pygame.sprite.Group()
all_sprite_list.add(player)
player.walls = wall_list
#Create enemies
for i in range(7):
block = Enemy("Judas.png")
block.rect.x = random.randrange(50, 950)
block.rect.y = random.randrange(50, 450)
block_list.add(block)
all_sprite_list.add(block)
#Manage screen updates
clock = pygame.time.Clock()
#Load background image
background_position = [0, 0]
background_image = pygame.image.load("Floor.png").convert()
#Loop until game_exit
done = False
#---------- MAIN PROGRAM LOOP ----------#
while not done:
# --- Event processing
for event in pygame.event.get():
if event.type == pygame.QUIT:
done = True
#Projectile spawn
elif event.type == pygame.KEYDOWN:
if event.key == pygame.K_UP:
projectile = ProjectileUp("LightningUp.png")
projectile.rect.x = player.rect.x+65
projectile.rect.y = player.rect.y
elif event.key == pygame.K_DOWN:
projectile = ProjectileDown("LightningDown.png")
projectile.rect.x = player.rect.x+65
projectile.rect.y = player.rect.y+100
elif event.key == pygame.K_LEFT:
projectile = ProjectileLeft("LightningLeft.png")
projectile.rect.x = player.rect.x+35
projectile.rect.y = player.rect.y+100
elif event.key == pygame.K_RIGHT:
projectile = ProjectileRight("LightningRight.png")
projectile.rect.x = player.rect.x+115
projectile.rect.y = player.rect.y+100
all_sprite_list.add(projectile)
projectile_list.add(projectile)
#Movement controls
if event.type == pygame.KEYDOWN:
if event.key == ord('a'):
player.changespeed(-7, 0)
elif event.key == ord('d'):
player.changespeed(7, 0)
elif event.key == ord('w'):
player.changespeed(0, -7)
elif event.key == ord('s'):
player.changespeed(0, 7)
elif event.type == pygame.KEYUP:
if event.key == ord('a'):
player.changespeed(7, 0)
elif event.key == ord('d'):
player.changespeed(-7, 0)
elif event.key == ord('w'):
player.changespeed(0, 7)
elif event.key == ord('s'):
player.changespeed(0, -7)
# --- Game logic
#Update sprites
all_sprite_list.update()
#Projectile mechanics
for projectile in projectile_list:
block_hit_list = pygame.sprite.spritecollide(projectile, block_list, True)
for block in block_hit_list:
projectile_list.remove(projectile)
#Determine if player hits enemy
blocks_hit_list = pygame.sprite.spritecollide(player, block_list, True)
#Call on background image
screen.blit(background_image, background_position)
# --- Draw the window
all_sprite_list.draw(screen)
pygame.display.flip()
clock.tick(60)
pygame.quit()

It's because your if/elif/else logic is messed up a bit. You have two paths for the KEYDOWN event. If the first event happens to be a movement command, your code runs through the projectile code first (without finding a valid projectile command) and then tries to reference a projectile object that doesn't exist. Try this instead:
#---------- MAIN PROGRAM LOOP ----------#
while not done:
# --- Event processing
for event in pygame.event.get():
if event.type == pygame.QUIT:
done = True
elif event.type == pygame.KEYDOWN:
projectile = None # initialize
if event.key == pygame.K_UP:
projectile = ProjectileUp("LightningUp.png")
projectile.rect.x = player.rect.x+65
projectile.rect.y = player.rect.y
elif event.key == pygame.K_DOWN:
projectile = ProjectileDown("LightningDown.png")
projectile.rect.x = player.rect.x+65
projectile.rect.y = player.rect.y+100
elif event.key == pygame.K_LEFT:
projectile = ProjectileLeft("LightningLeft.png")
projectile.rect.x = player.rect.x+35
projectile.rect.y = player.rect.y+100
elif event.key == pygame.K_RIGHT:
projectile = ProjectileRight("LightningRight.png")
projectile.rect.x = player.rect.x+115
projectile.rect.y = player.rect.y+100
elif event.key == ord('a'):
player.changespeed(-7, 0)
elif event.key == ord('d'):
player.changespeed(7, 0)
elif event.key == ord('w'):
player.changespeed(0, -7)
elif event.key == ord('s'):
player.changespeed(0, 7)
if projectile: # did we create a valid projectile?
all_sprite_list.add(projectile)
projectile_list.add(projectile)
elif event.type == pygame.KEYUP:
if event.key == ord('a'):
player.changespeed(7, 0)
elif event.key == ord('d'):
player.changespeed(-7, 0)
elif event.key == ord('w'):
player.changespeed(0, 7)
elif event.key == ord('s'):
player.changespeed(0, -7)

Pygame: bullets sticks to the screen

My problem is very simple. The bullets I fire sticks to the screen if I shoot fast. If I shoot slowly, they don't stick. Anyone have an idea how this phenomenon occurs?
screenshot of the bullets sticking to the screen
Below I have entered the code. I follow this default game flowchart:
I am curious about the origin of the problem. Is it the code or hardware?
import sys
import pygame
from pygame.sprite import Sprite
from pygame.sprite import Group
# pygame initializing
pygame.init()
#create the screen surface
screen = pygame.display.set_mode((800, 700))
class Color():
def __init__(self):
self.black = (0, 0, 0)
self.white = (255, 255, 255)
self.red = (255, 0, 0)
self.green = (0, 255, 0)
self.green_lambda = (10, 255, 150)
self.blue = (0, 0, 255)
# set up the colors
color = Color() # make an instance of this class - this makes some colors available
class Spaceship(Sprite):
"""
This class represents the Spaceship.
It derives from the "Sprite" class in Pygame.
"""
def __init__(self):
""" Constructor"""
# Call the parent class (Sprite) constructor
super().__init__()
width = 22
height = 32
self.screen = screen
self.image = pygame.Surface((width, height))
self.image.fill(color.black)
self.image.set_colorkey(color.black)
pygame.draw.polygon(self.image, color.green_lambda, [[10,0],[15,22],[20,30],[10,27],[0,30],[5,22]],2)
self.rect = self.image.get_rect()
self.screen_rect = self.screen.get_rect()
self.rect.centerx = self.screen_rect.centerx
self.rect.bottom = self.screen_rect.bottom
# As the rect method only take integers we store a
# This value is only used at the beginning, i.e. before the game loop starts
self.center_x = self.rect.centerx
self.center_y = self.rect.centery
class Bullet(Sprite):
"""
This class represents the bullets.
It derives from the "Sprite" class in Pygame.
"""
def __init__(self):
# Call the parent class (Sprite) constructor
super().__init__()
self.image = pygame.Surface((8,10))
self.image.fill(color.red)
self.image.set_colorkey((color.red))
pygame.draw.ellipse(self.image, color.green, [1, 0, 5, 8], 2)
self.rect = self.image.get_rect()
self.rect.centerx = defender.rect.centerx
self.rect.bottom = defender.rect.top
# def function to move the bullets
def update_pos(self):
self.rect.y -= bullet_speed
# create spaceship instance
defender = Spaceship()
# create group to store sprites in
all_sprites_list = Group()
all_sprites_list.add(defender)
ship_speed = 0.5
bullet_speed = 3
def run_game():
m_right = False
m_left = False
m_up = False
m_down = False
new_bullet = False
while True:
"""This is the user interaction section"""
for event in pygame.event.get():
if event.type == pygame.KEYDOWN:
if event.key == pygame.K_ESCAPE:
sys.exit()
elif event.key == pygame.K_RIGHT:
m_right = True
elif event.key == pygame.K_LEFT:
m_left = True
elif event.key == pygame.K_UP:
m_up = True
elif event.key == pygame.K_DOWN:
m_down = True
elif event.key == pygame.K_SPACE:
new_bullet = Bullet()
#print(dir(new_bullet))
all_sprites_list.add(new_bullet)
if event.type == pygame.KEYUP:
if event.key == pygame.K_RIGHT:
m_right = False
elif event.key == pygame.K_LEFT:
m_left = False
elif event.key == pygame.K_UP:
m_up = False
elif event.key == pygame.K_DOWN:
m_down = False
"""Below is the game logic, which gets input from the user interaction
section and more"""
# Movement of spaceship depending on the flag boolean value and on screen width and height
if m_right and defender.rect.right < defender.screen_rect.right:
defender.center_x += ship_speed
if m_left and defender.rect.left > defender.screen_rect.left:
defender.center_x -= ship_speed
if m_up and defender.rect.top > defender.screen_rect.top:
defender.center_y -= ship_speed
if m_down and defender.rect.bottom < defender.screen_rect.bottom:
defender.center_y += ship_speed
# The cumulative value (which is a float number) for the spaceships movement
# is given to the spaceship rect variable (which can only be integer) now.
# This enables fine adjusting of the speed
defender.rect.centerx = defender.center_x
defender.rect.centery = defender.center_y
all_sprites_list.update()
screen.fill(color.black)
if new_bullet:
new_bullet.update_pos()
# Below the bullets which leaves the screen display are deleted
if new_bullet.rect.bottom < defender.screen_rect.top:
all_sprites_list.remove(new_bullet)
all_sprites_list.draw(screen)
print(all_sprites_list)
pygame.display.flip()
run_game()

instead of just updating the position of new_bullet
# if new_bullet:
# new_bullet.update_pos()
# # Below the bullets which leaves the screen display are deleted
# if new_bullet.rect.bottom < defender.screen_rect.top:
# all_sprites_list.remove(new_bullet)
update the position of all bullets
for bullet in all_sprites_list:
if isinstance(bullet,Bullet):
bullet.update_pos()
if bullet.rect.bottom < defender.screen_rect.top:
all_sprites_list.remove(bullet)
del bullet

Joran Beasley's answer is correct. I'd just like to point out that you can also put the behavior of the sprites into their update methods which get called automatically when you call all_sprites_list.update(). You can actually move most of the code in the while loop to the update methods.
I've got an example with these changes and some more tips in the comments (a quick code review):
import pygame
from pygame.sprite import Sprite
from pygame.sprite import Group
# I'd just define some global constants for the colors.
BLACK = (0, 0, 0)
GREEN = (0, 255, 0)
GREEN_LAMBDA = (10, 255, 150)
class Spaceship(Sprite):
"""This class represents the Spaceship."""
def __init__(self, screen):
"""Constructor"""
super().__init__()
self.screen = screen
# pygame.SRCALPHA makes the surface transparent.
self.image = pygame.Surface((22, 32), pygame.SRCALPHA)
pygame.draw.polygon(
self.image, GREEN_LAMBDA,
[[10,0],[15,22],[20,30],[10,27],[0,30],[5,22]], 2
)
self.screen_rect = self.screen.get_rect()
# You can pass the position as the midbottom argument to `get_rect`.
self.rect = self.image.get_rect(midbottom=self.screen_rect.midbottom)
self.center_x = self.rect.centerx
self.center_y = self.rect.centery
# I've removed the `m_right`, etc. variables and just set the speed
# of the sprite in the event loop.
self.max_speed = 3.5
self.speed_x = 0
self.speed_y = 0
def update(self):
# Move the sprite.
self.center_x += self.speed_x
self.center_y += self.speed_y
self.rect.centerx = self.center_x
self.rect.centery = self.center_y
# Keep the sprite on the screen.
if not self.screen_rect.contains(self.rect):
self.rect.clamp_ip(self.screen_rect)
self.center_x, self.center_y = self.rect.center
class Bullet(Sprite):
"""This class represents the bullets."""
def __init__(self, pos):
super().__init__()
self.image = pygame.Surface((8, 10), pygame.SRCALPHA)
pygame.draw.ellipse(self.image, GREEN, [1, 0, 5, 8], 2)
self.rect = self.image.get_rect(midbottom=pos)
self.speed = 3 # The speed is now an attribute.
def update(self):
self.rect.y -= self.speed
if self.rect.top < 0:
self.kill() # Remove the sprite from all groups.
def run_game():
pygame.init()
screen = pygame.display.set_mode((800, 700))
clock = pygame.time.Clock() # Use a clock to limit the frame rate.
defender = Spaceship(screen)
all_sprites = Group() # Changed the name because groups are not lists.
all_sprites.add(defender)
while True:
for event in pygame.event.get():
if event.type == pygame.QUIT:
return
elif event.type == pygame.KEYDOWN:
if event.key == pygame.K_ESCAPE:
return
elif event.key == pygame.K_RIGHT:
defender.speed_x = defender.max_speed
elif event.key == pygame.K_LEFT:
defender.speed_x = -defender.max_speed
elif event.key == pygame.K_UP:
defender.speed_y = -defender.max_speed
elif event.key == pygame.K_DOWN:
defender.speed_y = defender.max_speed
elif event.key == pygame.K_SPACE:
new_bullet = Bullet(defender.rect.midtop) # Pass the pos.
all_sprites.add(new_bullet)
elif event.type == pygame.KEYUP:
if event.key == pygame.K_RIGHT and defender.speed_x > 0:
defender.speed_x = 0
elif event.key == pygame.K_LEFT and defender.speed_x < 0:
defender.speed_x = 0
elif event.key == pygame.K_UP and defender.speed_y < 0:
defender.speed_y = 0
elif event.key == pygame.K_DOWN and defender.speed_y > 0:
defender.speed_y = 0
all_sprites.update() # Calls the update methods of all sprites.
screen.fill(BLACK)
all_sprites.draw(screen)
pygame.display.flip()
clock.tick(60) # Limit the frame rate to 60 FPS.
run_game()

Pygame player movement stops when too many keys are pressed at the same time

When I try to move my character and press any other key at the same time, the movement suddenly stops. For example, the space key in my code is used to shoot a tiny orb out of the spaceship. Every time I press space and I am moving left and right quickly, the orb will shoot out but the player movement will be frozen for a second or two.
I have tried to switch to different ways of handling the way keys are input, but all of them seem to lead to this same problem. pygame.key.get_pressed() also has this problem when in my code.
I am not quite sure if this is a problem with my laptop keyboard or something in the code, so the code for the entire file is below.
import pygame, sys, decimal
# Screen Size
SCREEN_X = 400
SCREEN_Y = 400
# Loading Images
backgroundImg = pygame.image.load('StarBackground.png')
menuBar = pygame.image.load('Menu_Bar.png')
shipImg = pygame.image.load('PowerShip.png')
orb = pygame.image.load('Orb00.png')
class Ship(pygame.sprite.Sprite):
# Movement rate of change
change_x = 0
# Methods
def __init__(self):
pygame.sprite.Sprite.__init__(self)
self.image = shipImg.convert_alpha()
self.rect = self.image.get_rect()
self.rect.x = SCREEN_X / 2 - 8
self.rect.y = SCREEN_Y - 40
def move(self, speed):
self.change_x = speed
def stop(self):
self.change_x = 0
def update(self, screen):
self.rect.x += self.change_x
if self.rect.x < 0:
self.rect.x = 0
elif self.rect.right > SCREEN_X:
self.rect.x -= 1
screen.blit(self.image, self.rect)
class MenuBar(pygame.sprite.Sprite):
def __init__(self):
pygame.sprite.Sprite.__init__(self)
self.image = menuBar.convert_alpha()
self.rect = self.image.get_rect()
self.rect.x = 10
self.rect.y = 0
def update(self, screen):
screen.blit(self.image,self.rect)
class Bullet1(pygame.sprite.Sprite):
def __init__(self,x,y):
pygame.sprite.Sprite.__init__(self)
self.image = orb.convert_alpha()
self.rect = self.image.get_rect()
self.rect.x = x
self.rect.y = y
self.alive = True
def update(self):
if self.alive == True:
self.rect.y -= 1
if self.alive == False:
self.rect.y = -10000
class HealthBar(pygame.sprite.Sprite):
pass
class EnergyBar(pygame.sprite.Sprite):
pass
class PointsBar(pygame.sprite.Sprite):
pass
class Background(pygame.sprite.Sprite):
def __init__(self):
pygame.sprite.Sprite.__init__(self)
self.image = backgroundImg.convert_alpha()
self.rect = self.image.get_rect()
self.rect.x = 0
self.rect.y = 0
def update(self, screen):
if self.rect.top > 0:
self.rect.y = SCREEN_Y * -1
self.rect.y += 1
screen.blit(self.image, self.rect)
def main():
pygame.init()
size = [SCREEN_X, SCREEN_Y]
screen = pygame.display.set_mode(size, pygame.DOUBLEBUF) # Set the height and width of the screen
pygame.display.set_caption("Space Adventure") # Setting the game name in the title bar
background = Background() # Creating the game objects
menubar = MenuBar()
ship = Ship()
finished = False # Close button exit code
bullet1Enabled = True
bullet1Count = 1
spacePressed = False
clock = pygame.time.Clock() # Manages the frames per second
lastkey = None # Variable that stores the last key pressed
bulletlist = []
# Game loop
while not finished:
for event in pygame.event.get():
print(lastkey)
if event.type == pygame.QUIT:
finished = True
pygame.event.set_blocked(pygame.MOUSEMOTION)
if event.type == pygame.KEYDOWN:
if lastkey != pygame.K_SPACE:
lastkey = event.key
if event.key == pygame.K_SPACE:
spacePressed = True
if bullet1Enabled == True:
bullet1 = Bullet1(ship.rect.x, ship.rect.y)
bulletlist.append(bullet1)
bullet1Count = 1
else:
spacePressed = False
if event.type == pygame.KEYUP:
if event.key == pygame.K_RIGHT and lastkey != pygame.K_LEFT:
lastkey = None
ship.move(0)
if event.key == pygame.K_LEFT and lastkey != pygame.K_RIGHT:
lastkey = None
ship.move(0)
if event.key == pygame.K_RIGHT or lastkey == pygame.K_LEFT:
spacePressed = False
if event.key == pygame.K_LEFT or lastkey == pygame.K_RIGHT:
spacePressed = False
#Bullet Delay
if spacePressed == True:
bullet1Count = True
if spacePressed == False:
bullet1Count = False
if lastkey == pygame.K_RIGHT:
ship.move(1)
if lastkey == pygame.K_LEFT:
ship.move(-1)
clock.tick(240) # Frames per second
background.update(screen) # Background update
# Menu Bar update
ship.update(screen) # Ship update
for b in bulletlist:
if b.rect.bottom <= 0:
b.alive = False
b.update()
screen.blit(b.image, b.rect)
menubar.update(screen)
pygame.display.flip() # Updates the display for everything
pygame.quit() # Clean shutdown on IDLE
if __name__ == "__main__":
main()

The problem occurs because you don't reset lastkey to None after you release the space bar, so you have to press left or right twice.
if event.type == pygame.KEYUP:
if event.key == pygame.K_SPACE:
lastkey = None
I don't see why you need the lastkey variable at all. I'd remove these lines from the main loop,
if lastkey == pygame.K_RIGHT:
ship.move(1)
if lastkey == pygame.K_LEFT:
ship.move(-1)
insert them in the event loop and change lastkey to event.key:
if event.type == pygame.KEYDOWN:
if event.key == pygame.K_RIGHT:
ship.move(1)
if event.key == pygame.K_LEFT:
ship.move(-1)
Now you should be able to remove the lastkey completely.