Argthtjtr

I'm trying to make the snake game in python, but sadly my snake and my apples aren't appearing on the screen, all i see is a gray screen with nothing on it, can you help me out? thanks!
P.S - i would like an explanation as well about why my current code isn't working so i would avoid it in the future, thanks again.

import pygame, sys, random, time

from pygame.locals import *



pygame.init()

mainClock = pygame.time.Clock()

windowWidth = 500

windowHeight = 500

windowSurface = pygame.display.set_mode((windowWidth, windowHeight), 0, 32)

red = (255, 0, 0)

green = (0, 255, 0)

color = (100, 100, 100)

snakeHead = [250, 250]

snakePosition = [[250, 250],[240, 250],[230, 250]]

applePosition = [random.randrange(1,50)*10,random.randrange(1,50)*10]



def collisionBoundarias(snakeHead):

    if snakeHead[0] >= 500 or snakeHead[0] < 0 or snakeHead[1] >= 500 or snakeHead[1] < 0:

        return 1

    else:

        return 0



def collisionSelf(SnakePosition):

    snakeHead = snakePosition[0]

    if snakeHead in snakePosition[1:]:

        return 1

    else:

        return 0



while True:

    windowSurface.fill(color)

    for event in pygame.event.get():

        if event.type == pygame.QUIT:

            pygame.quit()

            sys.exit()

        if event.type == pygame.KEYDOWN:

            if event.type == pygame.K_RIGHT or event.key == pygame.K_d:

                snakeHead[0] += 10

            if event.type == pygame.K_LEFT or event.key == pygame.K_a:

                snakeHead[0] -= 10

            if event.type == pygame.K_UP or event.type == pygame.K_w:

                snakeHead[1] += 10

            if event.type == pygame.K_DOWN or event.type == pygame.K_s:

                snakeHead[1] -= 10



    def displaySnake(snakePosition):

        for position in snakePosition:

            pygame.draw.rect(windowSurface   ,red,pygame.Rect(position[0],position[1],10,10))



    def display_apple(windowSurface, applePosition, apple):

        windowSurface.blit(apple ,(applePosition[0], applePosition[1]))



    snakePosition.insert(0,list(snakeHead))

    snakePosition.pop()





    def displayFinalScore(displayText, finalScore):

        largeText = pygame.font.Font('freesansbold.ttf',35)

        TextSurf = largeText.render(displayText, True, (255, 255, 255))

        TextRect = TextSurf.get_rect()

        TextRect.center = ((windowWidth/2),(windowHeight/2))

        windowSurface.blit(TextSurf, TextRect)

        pygame.display.update()

        time.sleep(2)



    def collisionApple(applePosition, score):

        applePosition = [random.randrange(1,50)*10,random.randrange(1,50)*10]

        score += 1

        return applePosition, score



    if snakeHead == applePosition:

        applePosition, score = collisionApple(applePosition, score)

        snakePosition.insert(0,list(snakeHead))





    pygame.display.update()

    clock = pygame.time.Clock()

    clock.tick(20)

As mentioned in the comments, the objects don't appear because you never draw them by calling the displaySnake and display_apple functions. It also makes no sense to define these functions in the while loop again and again.

Here's a fixed version of the code. I've changed the movement code, so that the snake moves continually each frame. (It could still be improved, but I tried to keep it simple.)

import pygame, sys, random, time

from pygame.locals import *





pygame.init()

mainClock = pygame.time.Clock()

windowWidth = 500

windowHeight = 500

windowSurface = pygame.display.set_mode((windowWidth, windowHeight), 0, 32)

clock = pygame.time.Clock()

red = (255, 0, 0)

green = (0, 255, 0)

color = (100, 100, 100)

snakeHead = [250, 250]

snakePosition = [[250, 250],[240, 250],[230, 250]]

applePosition = [random.randrange(1,50)*10,random.randrange(1,50)*10]

apple = pygame.Surface((10, 10))

apple.fill(green)

score = 0

speed = 10

# Define a velocity variable (a list or better a pygame.Vector2).

velocity = pygame.Vector2(speed, 0)





def collisionBoundarias(snakeHead):

    return snakeHead[0] >= 500 or snakeHead[0] < 0 or snakeHead[1] >= 500 or snakeHead[1] < 0





def collisionApple(applePosition, score):

    applePosition = [random.randrange(1,50)*10,random.randrange(1,50)*10]

    score += 1

    return applePosition, score





def displaySnake(snakePosition):

    for position in snakePosition:

        pygame.draw.rect(windowSurface, red, pygame.Rect(position[0], position[1], 10, 10))





def display_apple(windowSurface, applePosition, apple):

    windowSurface.blit(apple, (applePosition[0], applePosition[1]))





while True:

    # Event handling.

    for event in pygame.event.get():

        if event.type == pygame.QUIT:

            pygame.quit()

            sys.exit()

        if event.type == pygame.KEYDOWN:

            # Replace `type` with `key`.

            if event.key == pygame.K_RIGHT or event.key == pygame.K_d:

                velocity.x = speed

                velocity.y = 0

            if event.key == pygame.K_LEFT or event.key == pygame.K_a:

                velocity.x = -speed

                velocity.y = 0

            if event.key == pygame.K_UP or event.key == pygame.K_w:

                velocity.x = 0

                velocity.y = -speed

            if event.key == pygame.K_DOWN or event.key == pygame.K_s:

                velocity.x = 0

                velocity.y = speed



    # Game logic.

    snakeHead[0] += velocity.x  # Update the x-position every frame.

    snakeHead[1] += velocity.y  # Update the y-position every frame.

    snakePosition.insert(0, snakeHead)

    snakePosition.pop()



    if snakeHead == applePosition:

        applePosition, score = collisionApple(applePosition, score)

        snakePosition.insert(0, snakeHead)



    # Drawing.

    windowSurface.fill(color)

    displaySnake(snakePosition)

    display_apple(windowSurface, applePosition, apple)

    pygame.display.update()

    clock.tick(20)