We Keep Coding

my pygame window crashes whenever i added the sound/music in my game [duplicate]

This question already has answers here:
How can I play an mp3 with pygame?
(7 answers)
how to play wav file in python?
(5 answers)
Closed 5 months ago.
I'm not so sure why but my game screen window/pygame window sometimes freezes or is not responding because of the added SFX or music in my game. If I remove the SFX or music the game runs smoothly. Hoping that anyone can help me or at least tell me why it keeps freezing. Thanks very much.
The specific code for music and sounds in class Game can be found in load_data method, run method, and update method.
This is where you can find my music, target SFX when hit, bonus SFX when hit.
Below is from my main.py module
import pygame as py
import sys
from os import kill, path
from Setting import *
from Sprite import *
import random
#BUGs (BULLET DISAPPEAR WHEN PAUSED [PROBABLY FROM get_tick()])
#add highscore later in end screen
class Game():
def __init__(self):
py.mixer.pre_init(44100, -16, 1, 512)
py.init()
self.screen = py.display.set_mode((Width, Height),py.RESIZABLE)
py.display.set_caption("Hit Me!")
self.clock = py.time.Clock()
self.load_data()
self.score_value = 0
self.time_value = 90
self.paused = False
self.channel1 = py.mixer.Channel(1)
self.channel2 = py.mixer.Channel(2)
self.channel3 = py.mixer.Channel(3)
def draw_data(self, text, font_name, size, color, x, y,type=0, align="center", value=""):
font = py.font.Font(font_name, size)
if type == 0:
text_surface = font.render(text + str(value), True, color)
if self.paused == True:
text_surface.set_alpha(125)
else:
text_surface = font.render(text, True, color)
text_rect = text_surface.get_rect()
if align == "nw":
text_rect.topleft = (x, y)
if align == "ne":
text_rect.topright = (x, y)
if align == "sw":
text_rect.bottomleft = (x, y)
if align == "se":
text_rect.bottomright = (x, y)
if align == "n":
text_rect.midtop = (x, y)
if align == "s":
text_rect.midbottom = (x, y)
if align == "e":
text_rect.midright = (x, y)
if align == "w":
text_rect.midleft = (x, y)
if align == "center":
text_rect.center = (x, y)
self.screen.blit(text_surface, text_rect)
def load_data(self):
game_folder = path.dirname(__file__)
self.map_data = []
with open(path.join(game_folder, 'map.txt'), 'rt') as f:
for line in f:
self.map_data.append(line)
image_folder = path.join(game_folder, 'images')
sfx_folder = path.join(game_folder, 'sfx_music')
self.dim_screen = py.Surface(self.screen.get_size()).convert_alpha()
self.dim_screen.fill((0, 0, 0, 150))
self.player_img = py.image.load(
path.join(image_folder, character)).convert_alpha()
self.bullet_img = py.image.load(
path.join(image_folder, bullets)).convert_alpha()
self.target_img = py.image.load(
path.join(image_folder, targets)).convert_alpha()
self.target_img = py.transform.scale(
self.target_img, (TileSize + 20, TileSize + 20))
self.bonus_img = py.image.load(
path.join(image_folder, time)).convert_alpha()
self.bonus_img = py.transform.scale(
self.bonus_img, (TileSize + 30, TileSize + 30))
#sound loading
self.music = py.mixer.Sound(path.join(sfx_folder,background_music))
self.music.set_volume(0.25)
self.gun_sfx = py.mixer.Sound(path.join(sfx_folder,gun_sound))
self.bonus_sfx = py.mixer.Sound(path.join(sfx_folder,bonus_sound))
self.target_sfx = py.mixer.Sound(path.join(sfx_folder,target_sound))
self.gun_sfx.set_volume(0.4)
self.target_sfx.set_volume(0.5)
def new(self):
self.sprites = py.sprite.Group()
self.walls = py.sprite.Group()
self.grass = py.sprite.Group()
self.targets = py.sprite.Group()
self.bullets = py.sprite.Group()
self.bonuss = py.sprite.Group()
for row, tiles in enumerate(self.map_data):
for col, tile in enumerate(tiles):
if tile == 'P':
self.player = Player(self, col, row)
py.time.set_timer(py.USEREVENT, 1000)
def newTarget(self):
self.targets = py.sprite.Group()
for row, tiles in enumerate(self.map_data):
for col, tile in enumerate(tiles):
if tile == '.':
target_chances = random.randint(0, 100)
if target_chances <= 10: # 10% chance
tile = 'T'
if tile == 'M':
bonus_chances = random.randint(0,100)
if bonus_chances <= 5: # 5% chance bonus time (add 2 or 3 seconds to timer) [specified area]
tile = 'B'
if tile == 'T':
Target(self, col, row)
if tile == 'B':
Bonus(self,col,row)
def run(self):
self.playing = True
self.music_played = False
if not self.music_played:
self.channel3.play(self.music, loops = -1)
self.music_played = True
while self.playing:
self.dt = self.clock.tick(FPS) / 1000
self.events()
if not self.paused:
self.update()
self.channel3.unpause()
if self.paused:
self.channel3.pause()
self.draw()
def quit(self):
py.quit()
sys.exit()
def update(self):
self.sprites.update()
hits = py.sprite.groupcollide(
self.targets, self.bullets, True, True, py.sprite.collide_mask)
bonus_hits = py.sprite.groupcollide(
self.bonuss, self.bullets, True, True, py.sprite.collide_mask)
#for bullets & targets
for hit in hits:
hit.kill()
self.score_value += 1
self.target_sfx_played = False
if not self.target_sfx_played:
self.channel1.play(self.target_sfx)
self.target_sfx_played = True
#for bullets & bonus
for hit in bonus_hits:
hit.kill()
self.time_value += 3
self.bonus_sfx_played = False
if not self.bonus_sfx_played:
self.channel2.play(self.bonus_sfx)
self.bonus_sfx_played = True
#if there is no target in screen, it will create a new set
if len(self.targets) == 0:
self.newTarget()
def drawGrid(self):
for x in range(0, Width, TileSize):
py.draw.line(self.screen, Black, (x, 0), (x, Height))
for y in range(0, Height, TileSize):
py.draw.line(self.screen, Black, (0, y), (Width, y))
def draw(self):
py.display.set_caption("{:.2f}".format(self.clock.get_fps()))
self.screen.fill(BGcolor)
self.drawGrid()
self.sprites.draw(self.screen)
py.draw.rect(self.screen, Green, self.player.rect, 1)
if self.paused:
self.screen.blit(self.dim_screen, (0, 0))
self.draw_data("Paused",'freesansbold.ttf', 105, White, Width / 2, Height / 2,1)
self.draw_data("Score: ",'freesansbold.ttf', 40, White, 100, 35,value = self.score_value)
self.draw_data("Time: ",'freesansbold.ttf', 40, White, 450, 35 ,value = self.time_value)
self.draw_data("HighScore: ",'freesansbold.ttf', 40, White, Width - 225, 35) # add data in end game
py.display.flip()
def events(self):
for event in py.event.get():
if event.type == py.QUIT:
self.quit()
if event.type == py.KEYDOWN:
if event.key == py.K_ESCAPE:
self.paused = not self.paused
if event.type == py.MOUSEBUTTONDOWN:
if event.button == 1:
if not self.paused:
self.player.shoot()
if event.type == py.USEREVENT:
if not self.paused:
self.time_value -=1
def show_start_screen(self):
pass
def show_go_screen(self):
pass
# main loop
g = Game()
g.show_start_screen()
while True:
g.new()
g.run()
g.show_go_screen()
In the Sprite.py module, this is where you can find the SFX for gun shooting whenever I press/hold the left mouse button.
Below is from my Sprite.py module
import pygame as py
from Setting import *
from pygame.locals import *
vec = py.math.Vector2
class Player(py.sprite.Sprite):
def __init__(self, game,x,y):
self.groups = game.sprites
py.sprite.Sprite.__init__(self, self.groups)
self.game = game
self.orig_image = game.player_img
self.rect = self.orig_image.get_rect()
self.pos = vec(x,y) * TileSize
self.rect.center = self.pos
self.last_shot = 0
self.gun_sfx = game.gun_sfx
self.channel4 = py.mixer.Channel(4)
def shoot(self):
if py.mouse.get_pressed()[0]:
now = py.time.get_ticks()
if now - self.last_shot > bullet_rate:
self.gun_sfx_played = False
if not self.gun_sfx_played:
self.channel4.play(self.gun_sfx)
self.gun_sfx_played = True
self.last_shot = now
dir = py.mouse.get_pos() - self.pos
radius, angle = dir.as_polar()
direction = vec(1, 0).rotate(angle - 3)
pos = self.pos + Barrel_offset.rotate(angle)
Bullet(self.game, pos, direction, -angle)
def rotate(self):
dir = py.mouse.get_pos() - self.pos
radius, angle = dir.as_polar()
self.image = py.transform.rotate(self.orig_image, -angle)
self.rect = self.image.get_rect(center=self.rect.center)
def update(self):
self.shoot()
self.rotate()
Below is from my Setting.py
# sounds
gun_sound = 'gun_sfx.mp3'
background_music = 'bg_music.mp3'
target_sound = 'target_sfx_broken.mp3'
bonus_sound = 'hourglass_sfx.mp3'

Pygame: Sprites spawn close to each other [duplicate]

Right now, my game blits all the images in random positions correctly and also gets the rect of the images correctly, but I can´t figure out how to use colliderect to make sure the images don´t overlap. How could it work for my code?
Also I´m trying to make the first text fade out and I don´t know why it doesn´t work for me.
Here is the code:
class GAME1:
def __init__(self, next_scene):
self.background = pygame.Surface(size)
# Create an array of images with their rect
self.images = []
self.rects = []
self.imagenes1_array = ['autobus.png','coche.png','barco.png','autobus2.png','grua.png','bici.png']
for i in self.imagenes1_array:
# We divide in variables so we can then get the rect of the whole Img (i2)
i2 = pygame.image.load(i)
self.images.append(i2)
s = pygame.Surface(i2.get_size())
r = s.get_rect()
# Trying to use colliderect so it doesnt overlap
if pygame.Rect.colliderect(r,r) == True:
x = random.randint(300,1000)
y = random.randint(200,700)
self.rects.append(r)
def start(self, gamestate):
self.gamestate = gamestate
for rect in self.rects:
# Give random coordinates (we limit the dimensions (x,y))
x = random.randint(300,1000)
y = random.randint(200,700)
rect.x = x
rect.y = y
def draw(self,screen):
self.background = pygame.Surface(size)
font = pygame.font.SysFont("comicsansms",70)
# First half (Show image to remember)
text1 = font.render('¡A recordar!',True, PURPLE)
text1_1 = text1.copy()
# This surface is used to adjust the alpha of the txt_surf.
alpha_surf = pygame.Surface(text1_1.get_size(), pygame.SRCALPHA)
alpha = 255 # The current alpha value of the surface.
if alpha > 0:
alpha = max(alpha-4, 0)
text1_1 = text1.copy()
alpha_surf.fill((255, 255, 255, alpha))
text1_1.blit(alpha_surf, (0,0), special_flags = pygame.BLEND_RGBA_MULT)
screen.blit(text1_1, (600,50))
# Second half (Show all similar images)
text2 = font.render('¿Cuál era el dibujo?',True, PURPLE)
#screen.blit(text2, (500,50))
for i in range(len(self.images)):
#colliding = pygame.Rect.collidelistall(self.rects)
screen.blit(self.images[i], (self.rects[i].x, self.rects[i].y))
def update(self, events, dt):
for event in events:
if event.type == pygame.MOUSEBUTTONDOWN:
for rect in self.rects:
if rect.collidepoint(event.pos):
print('works!')

Use collidelist() to test test if one rectangle in a list intersects:
for i in self.imagenes1_array:
s = pygame.image.load(i)
self.images.append(s)
r = s.get_rect()
position_set = False
while not position_set:
r.x = random.randint(300,1000)
r.y = random.randint(200,700)
margin = 10
rl = [rect.inflate(margin*2, margin*2) for rect in self.rects]
if len(self.rects) == 0 or r.collidelist(rl) < 0:
self.rects.append(r)
position_set = True
See the minimal example, that uses the algorithm to generate random not overlapping rectangles:
import pygame
import random
pygame.init()
window = pygame.display.set_mode((400, 400))
clock = pygame.time.Clock()
def new_recs(rects):
rects.clear()
for _ in range(10):
r = pygame.Rect(0, 0, random.randint(30, 40), random.randint(30, 50))
position_set = False
while not position_set:
r.x = random.randint(10, 340)
r.y = random.randint(10, 340)
margin = 10
rl = [rect.inflate(margin*2, margin*2) for rect in rects]
if len(rects) == 0 or r.collidelist(rl) < 0:
rects.append(r)
position_set = True
rects = []
new_recs(rects)
run = True
while run:
clock.tick(60)
for event in pygame.event.get():
if event.type == pygame.QUIT:
run = False
elif event.type == pygame.KEYDOWN:
new_recs(rects)
window.fill(0)
for r in rects:
pygame.draw.rect(window, (255, 0, 0), r)
pygame.display.flip()
pygame.quit()
exit()

Putting the scrolling camera in a mini-window in pygame

I'm trying to create a game where the action is shown in a little box within the main screen object, freeing up the surrounding space for text and menus and what-not. Since the map is larger than the allotted window, I coded a basic "camera" that follows the player around. It mostly works, but I'm having trouble "trimming off" the area outside of this window.
Here's the relevant bits of code (EDITED to provide Working Example):
import pygame, os, sys
from pygame.locals import *
pygame.init()
RIGHT = 'RIGHT'
LEFT = 'LEFT'
UP = 'UP'
DOWN = 'DOWN'
class Camera():
def __init__(self, screen, x_ratio = 1, y_ratio = 1, x_offset = 0, y_offset = 0):
self.screen = screen.copy()
self.rec = self.screen.get_rect()
self.rec.width *= x_ratio
self.rec.height *= y_ratio
self.x_offset = x_offset
self.y_offset = y_offset
def get_pos(self):
return (self.x_offset - self.rec.x, self.y_offset - self.rec.y)
def get_window(self):
w = pygame.Rect(self.rec)
w.topleft = (0 - self.rec.x, 0 - self.rec.y)
return w
def move(self, x, y):
"""Move camera into new position"""
self.rec.x = x
self.rec.y = y
def track(self, obj):
while obj.rec.left < self.rec.left:
self.rec.x -= 1
while obj.rec.right > self.rec.right:
self.rec.x += 1
while obj.rec.top < self.rec.top:
self.rec.y -= 1
while obj.rec.bottom > self.rec.bottom:
self.rec.y += 1
class Map:
def __init__(self, width, height):
self.width = width
self.height = height
self.rec = pygame.Rect(0,0,self.width,self.height)
def draw(self, screen):
pygame.draw.rect(screen, (200,200,200), self.rec)
class Obj:
def __init__(self, char, x = 0, y = 0, width = 0, height = 0):
self.width = width
self.height = height
self.rec = pygame.Rect(x, y, width, height)
self.cur_map = None
self.timers = {}
#Dummying in chars for sprites
self.char = char
self.x_dir = 1
self.y_dir = 1
self.speed = 1
self.moving = False
def move(self):
if self.x_dir != 0 or self.y_dir != 0:
new_x = self.rec.x + (self.x_dir*self.speed)
new_y = self.rec.y + (self.y_dir*self.speed)
new_rec = pygame.Rect(new_x, new_y, self.width, self.height)
#Keep movement within bounds of map
while new_rec.left < self.cur_map.rec.left:
new_rec.x += 1
while new_rec.right > self.cur_map.rec.right:
new_rec.x -= 1
while new_rec.top < self.cur_map.rec.top:
new_rec.y += 1
while new_rec.bottom > self.cur_map.rec.bottom:
new_rec.y -= 1
self.rec = new_rec
def set_dir(self, d):
self.x_dir = 0
self.y_dir = 0
if d == LEFT:
self.x_dir = -1
elif d == RIGHT:
self.x_dir = 1
elif d == UP:
self.y_dir = -1
elif d == DOWN:
self.y_dir = 1
def set_moving(self, val = True):
self.moving = val
class Game:
def __init__(self):
self.screen_size = (800, 600)
self.screen = pygame.display.set_mode(self.screen_size)
self.map_screen = self.screen.copy()
self.title = 'RPG'
pygame.display.set_caption(self.title)
self.camera = Camera(self.screen, 0.75, 0.75)#, 10, 75)
self.fps = 80
self.clock = pygame.time.Clock()
self.debug = False
self.bg_color = (255,255,255)
self.text_size = 18
self.text_font = 'Arial'
self.text_style = pygame.font.SysFont(self.text_font, self.text_size)
self.key_binds = {LEFT : [K_LEFT, K_a], RIGHT : [K_RIGHT, K_d], UP : [K_UP, K_w], DOWN : [K_DOWN, K_s],
'interact' : [K_RETURN, K_z], 'inventory' : [K_i, K_SPACE], 'quit' : [K_ESCAPE]}
self.player = Obj('p', 0, 0, 10, self.text_size)
def draw(self, obj):
char = obj.char
self.draw_text(char, obj.rec.x, obj.rec.y, screen = self.map_screen)
def draw_text(self, text, x, y, color = (0,0,0), screen = None):
textobj = self.text_style.render(text, 1, color)
textrect = textobj.get_rect()
textrect.x = x
textrect.y = y
if screen == None:
"""Use default screen"""
self.screen.blit(textobj, textrect)
else:
screen.blit(textobj, textrect)
def play(self):
done = False
cur_map = Map(800, 800)
self.map_screen = pygame.Surface((cur_map.width, cur_map.height))
self.map_screen.fill(self.bg_color)
bg = pygame.Surface((cur_map.width, cur_map.height))
cur_map.draw(bg)
self.player.cur_map = cur_map
while not done:
for event in pygame.event.get():
if event.type == QUIT:
pygame.quit()
sys.exit()
if event.type == KEYDOWN:
if event.key in self.key_binds[LEFT]:
self.player.set_dir(LEFT)
self.player.set_moving()
elif event.key in self.key_binds[RIGHT]:
self.player.set_dir(RIGHT)
self.player.set_moving()
elif event.key in self.key_binds[UP]:
self.player.set_dir(UP)
self.player.set_moving()
elif event.key in self.key_binds[DOWN]:
self.player.set_dir(DOWN)
self.player.set_moving()
elif event.type == KEYUP:
self.player.set_moving(False)
if self.player.moving:
self.player.move()
self.camera.track(self.player)
self.clock.tick()
self.screen.fill(self.bg_color)
self.map_screen.blit(bg, (0,0))
self.draw(self.player)
pygame.draw.rect(self.map_screen, (0,0,0), self.camera.rec, 1)
#self.screen.blit(self.map_screen, (0,0), [0 - self.camera.rec.x, 0 - self.camera.rec.y, self.camera.rec.width, self.camera.rec.height])
self.screen.blit(self.map_screen, self.camera.get_pos(), self.camera.get_window())
pygame.display.flip()
game = Game()
game.play()
Moving the player past past the bounds of the camera's window causes the window to roll up completely and disappear. I tried adjusting the blitting coordinates, as advised earlier, but it seems to only change the direction in which the window rolls up.

From your updated code, the blitting coordinates for self.screen.blit(...) are still changing: self.camera.get_window() changes value because rec.x and rec.y are values referring to the player position within the map. Hence you should define a constant minimap coordinate, this should be the same as the camera offset.
self.screen.blit(self.map_screen, (self.camera.x_offset,self.camera.y_offset), (*self.camera.get_pos(), self.camera.rec.width, self.camera.rec.height))
Change the Camera().get_pos() to:
def get_pos(self):
return (self.rec.x, self.rec.y)
I believe I only changed the self.screen.blit(...) and stopped using or rewrote your Camera functions as you're confusing yourself with all the rec variables.
To illustrate it working amend the Map().draw(screen) to:
def draw(self, screen):
pygame.draw.rect(screen, (200,200,200), self.rec)
pygame.draw.circle(screen, (255, 255, 255), (50, 50), 20, 2)
One tip as well don't draw the entire map at each loop, just the part that will be visible.

Pygame. How to make a rect change direction on collision (boundary check)

Part of an assignment I'm working on is making a ball bounce around the screen, I can make it move, but my boundary test doesn't seem to be working: the ball simply moves in direction instead of changing direction. So to clarify, what I want to ball to do is change direction as it hits the screen edge.
import sys
import pygame
SCREEN_SIZE = 750, 550
BALL_DIAMETER = 16
BALL_RADIUS = BALL_DIAMETER // 2
MAX_BALL_X = SCREEN_SIZE[0] - BALL_DIAMETER
MAX_BALL_Y = SCREEN_SIZE[1] - BALL_DIAMETER
BLACK = (0, 0, 0)
WHITE = (255, 255, 255)
LEFT = 11
RIGHT = 12
pygame.init()
clock = pygame.time.Clock()
pygame.display.init()
font = pygame.font.SysFont("impact", 20)
pygame.display.set_caption("Breakout")
screen = pygame.display.set_mode(SCREEN_SIZE)
class Ball:
def __init__(self):
''' '''
self.ball = pygame.Rect(300, 730 -
BALL_DIAMETER,
BALL_DIAMETER, BALL_DIAMETER)
# Draw ball
def draw_ball(self):
pygame.draw.circle(screen,
WHITE, (self.ball.left
+ BALL_RADIUS, self.ball.top +
BALL_RADIUS), BALL_RADIUS)
# Updates the coordinates by adding the speed components
def move_ball(self, x, y):
self.xspeed = x
self.yspeed = y
self.ball = self.ball.move(self.xspeed, self.yspeed)
# bounds check
if self.ball.left <= 0:
self.ball.left = 0
self.xspeed = -self.xspeed
elif self.ball.left >= MAX_BALL_X:
self.ball.left = MAX_BALL_X
self.xspeed = -self.xspeed
if self.ball.top < 0:
self.ball.top = 0
self.yspeed = -self.yspeed
elif self.ball.top >= MAX_BALL_Y:
self.ball.top = MAX_BALL_Y
self.yspeed = -self.yspeed
# shows a message on screen, for testing purposes
class Text:
def show_message(self, message):
self.font = pygame.font.SysFont("impact", 20)
font = self.font.render(message,False, WHITE)
screen.blit(font, (200, 400))
class Game:
def __init__(self):
''' '''
def run(self):
b = Ball()
while 1:
for event in pygame.event.get():
if event.type == pygame.QUIT:
sys.exit()
keys = pygame.key.get_pressed()
# fps lock, screen fill and method call for input
clock.tick(60)
screen.fill(BLACK)
b.draw_ball()
b.move_ball(5, -5)
# used to keep track of various elements
# Text().show_message("P: " + str(p))
pygame.display.flip()
# Creates instance of the game class, and runs it
if __name__ == "__main__":
Game().run()

Your only call to move_ball uses a constant vector.
Since you never change the call parameters, the ball moves only that way.
b.move_ball(5, -5)
Yes, you change the vector components within move_ball when you hit a wall. However, on the next call, you change them back to the original values and move the ball in the original direction.
You have to initialize the vector outside move_ball, and then let the routine access the existing vector when it's called.

Python - How to speed up smoothness in pygame?

I'm wondering how to speed up the smoothness of my code written in Python using pygam. I'm guessing I have to make this more efficient somehow? When this is run, some balls move around randomly in a set area, however, the new position of each ball is not smooth at all, there is a jump between each movement as the cycle is very slow. How do I fix this? Or is there any suggestions on how to improve it?
This is my code so far:
import pygame
from pygame import *
import random
pygame.init()
size = width, height = 800, 600
screen = display.set_mode(size)
pygame.display.set_caption("Year 12: Ideal Gas Simulation")
BLACK = (0, 0, 0)
RED = (255, 0, 0)
BLUE = (0, 0, 255)
WHITE=(255,255,255)
GREEN = (0, 255, 0)
BALLX = 0
BALLY = 1
BALLSPEEDX = 2
BALLSPEEDY = 3
List=[]
radius=5
running=True
myClock=time.Clock()
myClock.tick(60)
def initBall():
for n in range(40):
ballx = random.randint(0, 800) # randomly setting the x position
bally = random.randint(0, 600) # randomly setting the y position
dirx = random.randint(-5,5) # randomly setting the x speed
diry = random.randint(-5,5) # randomly setting the y speed
data=[ballx, bally, dirx, diry]
List.append(data)
# returning a list with all the data the ball needs
return List # returning the list
def drawScreen(List):
draw.rect(screen, WHITE, (0, 0, 800, 600))
for x in range(40):
BALLX=List[x][0]
BALLY=List[x][1]
draw.circle(screen, GREEN, (BALLX,BALLY),radius)
display.flip()
pygame.draw.rect(screen, BLACK, (100-radius,100-radius,600+(2*radius),400+(2*radius)), 1)
f=pygame.font.SysFont(None,60)
text=f.render("PV=nRT",True,(0,0,0))
screen.blit(text,(300,height/20))
def moveBall(List):
for x in range(40):
BALLX=List[x][0]
BALLY=List[x][1]
SPEEDX=List[x][2]#####data[BALLX]== the first index of each list [x][0]
SPEEDY=List[x][3]##data[BALLSPEEDX]= List[x][2]
age=SPEEDX+BALLX
List[x][0]=age
# increases the position of the ball
plus=SPEEDY+BALLY
List[x][1]=plus
# checks to see if the ball is hitting the walls in the x direction
if BALLX > 700:
List[x][0] = 700#NORMALLY 800
third=List[x][2]
answer=third*-1
List[x][2]=answer
elif BALLX < 100:#NORMALLY 0
List[x][0] = 100
third=List[x][2]
answer=third*-1
List[x][2]=answer
# checks to see if the ball is hitting the walls in the y direction
if BALLY < 100:
List[x][1] = 100#NORMALLY 0
third=List[x][3]
answer=third*-1
List[x][3]=answer
elif BALLY > 500:
List[x][1] = 500#NORMALLY 600
third=List[x][3]
answer=third*-1
List[x][3]=answer
return List#return updated list
List=initBall()
while running==True:
for evnt in event.get():
if evnt.type==QUIT:
running=False
quit()
if evnt.type==MOUSEBUTTONDOWN:
mx,my=evnt.pos
button=evnt.button
drawScreen(List)
List=moveBall(List)

In addition to skrx's answer, you can also refactor the code and avoid a lot of duplicate calls. Also, indexing the BALLS array directly might improve performance slightly.
Generally, avoid naming variables inside functions with uppercase. These names are typically given to constants defined at the top of your file.
The version I came up with is below:
import array
import pygame
pygame.init()
import random
from pygame import *
size = WIDTH, HEIGHT = 800, 600
screen = display.set_mode(size)
pygame.display.set_caption("Year 12: Ideal Gas Simulation")
BLACK = (0, 0, 0)
RED = (255, 0, 0)
BLUE = (0, 0, 255)
WHITE = (255,255,255)
GREEN = (0, 255, 0)
BALLX = 0
BALLY = 1
BALLSPEEDX = 2
BALLSPEEDY = 3
RADIUS = 5
BALLS = []
myClock = time.Clock()
myClock.tick(60)
def initBalls():
for n in range(40):
props = array.array('i', [
random.randint(0, WIDTH),
random.randint(0, HEIGHT),
random.randint(-5, 5),
random.randint(-5, 5),
])
BALLS.append(props)
def drawScreen():
draw.rect(screen, WHITE, (0, 0, 800, 600))
props = (100-RADIUS, 100-RADIUS, 600+(2*RADIUS), 400+(2*RADIUS))
pygame.draw.rect(screen, BLACK, props, 1)
f = pygame.font.SysFont(None, 60)
text = f.render("PV=nRT", True,(0, 0, 0))
screen.blit(text,(300, HEIGHT / 20))
for i in range(len(BALLS)):
draw.circle(screen, GREEN, BALLS[i][:2],RADIUS)
display.flip()
def moveBalls():
for i in range(len(BALLS)):
if BALLS[i][0] > 700:
BALLS[i][0] = 700
BALLS[i][2] *= -1
elif BALLS[i][0] < 100:
BALLS[i][0] = 100
BALLS[i][2] *= -1
else:
BALLS[i][0] += BALLS[i][2]
if BALLS[i][1] < 100:
BALLS[i][1] = 100
BALLS[i][3] *= -1
elif BALLS[i][1] > 500:
BALLS[i][1] = 500
BALLS[i][3] *= -1
else:
BALLS[i][1] += BALLS[i][3]
def main():
initBalls()
while True:
for evnt in event.get():
if evnt.type == QUIT:
pygame.quit()
return
elif evnt.type == MOUSEBUTTONDOWN:
mx, my = evnt.pos
button = evnt.button
drawScreen()
moveBalls()
if __name__ == "__main__":
main()

Call pygame.display.flip() only once per frame.
def drawScreen(List):
draw.rect(screen, WHITE, (0, 0, 800, 600))
for x in range(40):
BALLX=List[x][0]
BALLY=List[x][1]
draw.circle(screen, GREEN, (BALLX,BALLY),radius)
# display.flip() # Don't call `display.flip()` here.
pygame.draw.rect(screen, BLACK, (100-radius,100-radius,600+(2*radius),400+(2*radius)), 1)
screen.blit(text,(300,height/20))
pygame.display.flip() # Call it here.
I also recommend to use a pygame.time.Clock to limit the frame rate.
# Define the font object as a global constant.
FONT = pygame.font.SysFont(None, 60)
# If the text doesn't change you can also define it here.
TEXT = FONT.render("PV=nRT", True, (0,0,0))
# Instantiate a clock to limit the frame rate.
clock = pygame.time.Clock()
running = True
while running: # `== True` is not needed.
for evnt in event.get():
if evnt.type == QUIT:
running = False
# Better use `pygame.quit` and `sys.exit` to quit.
pygame.quit()
sys.exit()
drawScreen(List)
List = moveBall(List)
clock.tick(30) # Limit frame rate to 30 fps.