[Python] Pygame Snake Splitting Bug [closed]

import pygame
import random
pygame.init()

#game is 64 cells x 32 cells
width = 64
height = 32

WIDTH = width * 20
HEIGHT = height * 20
FPS = 60

screen = pygame.display.set_mode((WIDTH, HEIGHT))
pygame.display.set_caption("Snake")

clock = pygame.time.Clock()

RED = (255, 0, 0)
GREEN = (0, 255, 0)
BEIGE = (232, 220, 202)
ORANGE = (255, 165, 0)

blockHeight = HEIGHT / height
blockWidth = WIDTH / width

class Fruit:
def __init__(self):
self.xpos = random.randint(1, width) * blockWidth
self.ypos = random.randint(0, height - 1) * blockHeight
self.FruitRect = pygame.Rect(self.xpos, self.ypos, blockWidth, blockHeight)
self.Fruit = pygame.draw.rect(screen, ORANGE, self.FruitRect)

def __str__(self):
return f"fruit: x: {self.xpos}, y: {self.ypos}"

def draw(self):
self.FruitRect = pygame.Rect(self.xpos, self.ypos, blockWidth, blockHeight)
self.Fruit = pygame.draw.rect(screen, ORANGE, self.FruitRect)

def eat(self, snakePos):
self.xpos = random.randint(1, width) * blockWidth
self.ypos = random.randint(0, height - 1) * blockHeight
if (self.xpos, self.ypos) in snakePos:
while (self.xpos, self.ypos) in snakePos:
self.xpos = random.randint(1, width) * blockWidth
self.ypos = random.randint(0, height - 1) * blockHeight

def returnPos(self):
return self.xpos, self.ypos

class Head:
def __init__(self):
self.xpos = width // 2 * blockWidth
self.ypos = height // 2 * blockHeight
self.HeadRect = pygame.Rect(self.xpos, self.ypos, blockWidth, blockHeight)
self.Head = pygame.draw.rect(screen, RED, self.HeadRect)

def __str__(self):
return f"head: x: {self.xpos}, y: {self.ypos}"

def draw(self):
self.HeadRect = pygame.Rect(self.xpos, self.ypos, blockWidth, blockHeight)
self.Head = pygame.draw.rect(screen, RED, self.HeadRect)

def update(self, xFac, yFac):
self.xpos += blockWidth * xFac
self.ypos += blockHeight * yFac

def returnPos(self):
return self.xpos, self.ypos

class Body:
def __init__(self, xpos, ypos):
self.xpos = xpos
self.ypos = ypos
self.BodyRect = pygame.Rect(self.xpos, self.ypos, blockWidth, blockHeight)
self.Body = pygame.draw.rect(screen, GREEN, self.BodyRect)

def __str__(self):
return f"body: x: {self.xpos}, y: {self.ypos}"

def draw(self):
self.BodyRect = pygame.Rect(self.xpos, self.ypos, blockWidth, blockHeight)
self.Body = pygame.draw.rect(screen, GREEN, self.BodyRect)

def update(self, xFac, yFac):
self.xpos += blockWidth * xFac
self.ypos += blockHeight * yFac

def returnPos(self):
return self.xpos, self.ypos


def main():
run = True
screen.fill(BEIGE)
snake = Head()
yVel = 0
xVel = 0
time = 0
fruits = [Fruit(), Fruit(), Fruit(), Fruit(), Fruit()]
snakeParts = [snake]
snakeVels = [(xVel, yVel)]
while run:
clock.tick(FPS)
time += 1
if time == FPS:
time = 0

for fruit in fruits:
if snake.returnPos() == fruit.returnPos():
snakePos = []
for snakePart in snakeParts:
snakePos.append(snakePart.returnPos())
fruit.eat(snakePos)
snakeParts.append(Body(snakeParts[-1].returnPos()[0], snakeParts[-1].returnPos()[1])) #add a body part
snakeVels.append((0, 0)) #the velocity of the new body part is 0
fruit.draw()

for snakePart in snakeParts:
if snakePart.returnPos() == snake.returnPos() and snakePart != snakeParts[0] and len(snakeParts) != 2:
run = False #if the snake hits itself, the game ends
snakePart.draw()
if snake.returnPos()[0] < 0 or snake.returnPos()[0] + blockWidth > WIDTH or snake.returnPos()[1] < 0 or snake.returnPos()[1] + blockHeight > HEIGHT:
run = False #if the snake goes off the edge of the screen, the game ends
pygame.display.update()

if time == 0 or time == FPS // 2: #twice a second...
screen.fill(BEIGE)
#update the velocoties (add one new velcoity at the front and remove the last one)
snakeVels.insert(0, (xVel, yVel))
if snakeVels[-1] == (0, 0) and len(snakeParts) != 1:
#if the last velocity is 0, make the second to last velocity 0 in order to be able to remove the last velocity
#this is a list instead of a tuple so next iteration it is removed and the velocity does not stay at 0
snakeVels[-2] = [0, 0]
snakeVels.remove(snakeVels[-1])
for i in range(len(snakeParts)):
snakeParts.update(snakeVels[0], snakeVels[1]) #update the position of each body part based on its corresponding velocity

#my attempted debugging
print(snakeVels)
snakePartsString = []
for snakePart in snakeParts:
snakePartsString.append(str(snakePart))
print(snakePartsString)

for event in pygame.event.get():
if event.type == pygame.QUIT:
run = False
if event.type == pygame.KEYDOWN:
if event.key == pygame.K_LEFT:
xVel = -1
yVel = 0
if event.key == pygame.K_RIGHT:
xVel = 1
yVel = 0
if event.key == pygame.K_UP:
xVel = 0
yVel = -1
if event.key == pygame.K_DOWN:
xVel = 0
yVel = 1

main()
pygame.quit()



The issue is when you enter multiple inputs (press arrows) in quick succession, the snake will sometimes split. Even when you're not entering inputs it can split. Entering inputs just increases the chance of it splitting. I think that the issue is with the event handling or the way velocities are added, removed, and used in the snakeVels list. When printing the snakeVels list, you can see that the velocities aren't always changed properly after turns.

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