I’m trying to detect collision between two classes I’ve created in PyGame, and on collision, delete the objects from their respective lists. However, I cannot get the collision detection to work. Any help would be greatly appreciated.

import pygame
import sys

WIDTH = 800
HEIGHT = 600
GROUND = 500

pygame.init()

# set the screen, caption, clock, font, basic surfaces
screen = pygame.display.set_mode((WIDTH, HEIGHT))
pygame.display.set_caption('Snail Jumper')
clock = pygame.time.Clock()
test_font = pygame.font.Font('Pixeltype.ttf', 50)
sky = pygame.Surface((800, GROUND))
sky.fill('Light Blue')
groundImage = pygame.image.load('ground.png')

# Timer
currentTime = 0
timeSurface = test_font.render(f'{currentTime}', False, (64,64,64))

# Snail Essentials
snailImage = pygame.image.load('snail1.png')
snailX = GROUND
snailY = 665
snail = snailImage.get_rect(bottomleft=(snailY, snailX))
snailXSpeed = -4
snailYSpeed = 0

# Jump/Gravity Variables
playerVelocity = 0
jumpVelocity = -16
gravity = 1
snailStatus = 0
jump = 1
offsetCooldown = 100

# Obstacle variables
obstacles = []
nextOffset = 0
obstacleDimen = 20
obstacleCooldown = 0
bullets = []
xVel = -8
yVel = 0
bulletX = 0
bulletY = 30
bulletCount = 1

# Collisions
hits = 0
hitSurface = test_font.render(f'Collisions: {hits}', False, 'Black')
collideSound = pygame.mixer.Sound("punch.wav")

# Obstacle Class
class Obstacle(object):
    def __init__(self,x,y,width,height):
        self.x = x
        self.y = y
        self.width = width
        self.height = height
        self.xSpeed = 2.5
        self.ySpeed = 0
        self.color = (23,23,23)
        self.rect = pygame.Rect(x,y,width,height)
    
    def draw(self,scrn):
        pygame.draw.rect(scrn, self.color, (self.x, self.y, self.width,self.height))
    
    def getRect(self):
        return self.rect.copy()
    

class projectile(object):
    def __init__(self,x,y,radius,color,xVel,yVel):
        self.x = x
        self.y = y
        self.radius = radius
        self.color = color
        self.xVel = xVel
        self.yVel = yVel
        self.rect = pygame.Rect(x,y,radius,radius)

    def draw(self,scrn):
        pygame.draw.circle(scrn, self.color, (self.x,self.y), self.radius)
        
    def getRect(self):
        return self.rect.copy()
    
    def collidesWith(self, otherRect):
        result = self.rect.colliderect(otherRect)
        if result:
            print("true")
        return result


running = True
while running:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            pygame.quit()
            exit()
        keys = pygame.key.get_pressed()
        if keys[pygame.K_SPACE] and jump > 0:
            playerVelocity = jumpVelocity
            jump -= 1
        # Projectiles
        bulletXOffset = snail.x + bulletX
        bulletYOffset = snail.y + bulletY
        if keys[pygame.K_f]:
            if bulletCount > 0:
                bullets.append(projectile(bulletXOffset, bulletYOffset, 6, (173,255,47),xVel,yVel))
                #bulletCount -= 1
                
    # Gravity logic
    if snailStatus == 0:
        playerVelocity += gravity
        snail.y += playerVelocity
        if snail.bottom >= GROUND:
            snail.bottom = GROUND
            playerVelocity = 0
            jump = 1
    elif snailStatus == 1:
        playerVelocity += gravity
        snail.x += playerVelocity
        if snail.left <= 0:
            snail.left = 0
            playerVelocity = 0
            jump = 1
    elif snailStatus == 2:
        playerVelocity += gravity
        snail.y += playerVelocity
        if snail.top <= 0:
            snail.top = 0
            playerVelocity = 0
            jump = 1
    else:
        playerVelocity += gravity
        snail.x += playerVelocity
        if snail.right >= WIDTH+36:
            snail.right = WIDTH+36
            playerVelocity = 0
            jump = 1


    if offsetCooldown > 0:
        offsetCooldown -= 1
    # Snail Rotation
    if snail.left < 0:
        snailXSpeed = 0
        snailYSpeed = -4
        snailImage = pygame.transform.rotate(snailImage,-90)
        snailStatus = 1
        jumpVelocity = 16
        gravity = -1
        snail.width = 36
        bulletY = 0
        bulletX = 6
        xVel = 0
        yVel = -8
    if snail.top < 0:
        snailXSpeed = 4
        snailYSpeed = 0
        snailImage = pygame.transform.rotate(snailImage,-90)
        snailStatus = 2
        snail.width = 72
        bulletX = 72
        bulletY = 6
        xVel = 8
        yVel = 0
    # Final two need offsets to account for image rect size
    if snail.right > WIDTH-10 and offsetCooldown <= 0 and snail.top < 200:
        offsetCooldown = 80
        snail.right = WIDTH+36
        snailXSpeed = 0
        snailYSpeed = 4
        snailImage = pygame.transform.rotate(snailImage,-90)
        snailStatus = 3
        jumpVelocity = -16
        gravity = 1
        bulletX = 30
        bulletY = 72
        xVel = 0
        yVel = 8
    if snail.bottom > GROUND-20 and offsetCooldown <= 0 and snail.right > 650:
        offsetCooldown = 80
        snail.bottom = GROUND
        snailXSpeed = -4
        snailYSpeed = 0
        snailImage = pygame.transform.rotate(snailImage,-90)
        snailStatus = 0
        bulletX = 0
        bulletY = 30
        xVel = -8
        yVel = 0
        
    # Obstacle Creation
    obstacleCooldown -= 1
    if obstacleCooldown <= 0 and (snail.bottom < 380 or snail.left > 200):
        obstacles.append(Obstacle(10+nextOffset, GROUND-obstacleDimen-nextOffset, obstacleDimen, obstacleDimen))
        if nextOffset == 0:
            nextOffset = 40
        else:
            nextOffset = 0
        obstacleCooldown = 350
    
    # Obstacle Movement
    for obst in obstacles:
        if (obst.y == GROUND-obstacleDimen and obst.x >= WIDTH-obstacleDimen) or (obst.y == GROUND-obstacleDimen-40 and obst.x >= WIDTH-40-obstacleDimen):
            obst.xSpeed = 0
            obst.ySpeed = -2.5
        if (obst.y == 0 and obst.x >= WIDTH-obstacleDimen) or (obst.y == 40 and obst.x == WIDTH-40-obstacleDimen):
            obst.xSpeed = -2.5
            obst.ySpeed = 0
        if (obst.y == 0 and obst.x <= 0) or (obst.y == 40 and obst.x <= 40):
            obst.xSpeed = 0
            obst.ySpeed = 2.5
        if (obst.y == GROUND-obstacleDimen and obst.x <= 0) or (obst.y == GROUND-obstacleDimen-40 and obst.x == 40):
            obst.xSpeed = 2.5
            obst.ySpeed = 0
            
    # Obstacle Collision
    for obst in obstacles:
        if snail.colliderect(obst.x,obst.y,obst.width,obst.height):
            obstacles.remove(obst)
            collideSound.play()
            hits += 1
            hitSurface = test_font.render(f'Collisions: {hits}', False, 'Black')
    for bullet in bullets:
        if bullet.collidesWith(obstacle.rect):
            obstacles.remove(obst)
            bullets.remove(bullet)
#             if hits == 10:
#                 gameActive = False
            
    for obst in obstacles:
        obst.x += obst.xSpeed
        obst.y += obst.ySpeed
    for bullet in bullets:
        bullet.x += bullet.xVel
        bullet.y += bullet.yVel
    snail.x += snailXSpeed
    snail.y += snailYSpeed
    
    #blits
    screen.blit(sky, (0, 0))
    screen.blit(groundImage, (0, GROUND))
    screen.blit(snailImage, snail)
    screen.blit(timeSurface, (375, 300))
    for obst in obstacles:
        obst.draw(screen)
    for bullet in bullets:
        bullet.draw(screen)
    currentTime = pygame.time.get_ticks()
    currentTime = int(currentTime/1000)
    timeSurface = test_font.render(f'{currentTime}', False, (64,64,64))
    
    pygame.display.update()
    clock.tick(60)  # sets a frame rate

The collision detection in the class functions are not performing as intended – it never prints the test string.

In the #Obstacle Collision section at the bottom of the code, I tried multiple solutions – the current code there now is just the latest attempt. I tried putting it within the “for obst” loop, and tried using rect.copy and many other methods, but nothing I’ve tried has worked and it never detects the collision between the obstacle and projectile.