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I'm pretty new to Python and really new to Pygame. My snake game runs, but I guess that's not really saying much. I would appreciate feedback on the layout, techniques, or best practices of my code.

import pygame,sys,random,time
from pygame.locals import *

#Setup pygames#
pygame.init()


#Setup the window#
WINDOWWIDTH = 400
WINDOWHEIGHT = 400
windowSurface = pygame.display.set_mode(
    (WINDOWWIDTH,WINDOWHEIGHT), 0, 32
    )
pygame.display.set_caption('Snake')
mainClock = pygame.time.Clock()

#Direction Variables#
U = 'up'
D = 'down'
L = 'left'
R = 'right'

#Set up the colors#
BLACK = (0,0,0)
WHITE = (255,255,255)
RED = (255,0,0)
GREEN = (0,255,0)
BLUE = (0,0,255)
YELLOW = (255,255,102)

#All the food code stuff#
FOODS = []
FOODSIZE = 10
FOODS.append(pygame.Rect(random.randint(FOODSIZE,WINDOWWIDTH-2*FOODSIZE),
        random.randint(FOODSIZE,WINDOWHEIGHT-2*FOODSIZE),FOODSIZE,FOODSIZE))

#Code for the game over screen#
font_style = pygame.font.SysFont(None, 50)
font_style1 = pygame.font.SysFont(None, 25)
score_font = pygame.font.SysFont('sfcompactroundedregularotf',25)

#function you call to dispplay the GAME OVER message#
def message(msg1,msg2,msg3,color):
    mesg1 = font_style.render(msg1,True,color)
    mesg2 = font_style1.render(msg2,True,color)
    mesg3 = font_style1.render(msg3,True,color)
    windowSurface.blit(mesg1,[WINDOWWIDTH/4, WINDOWHEIGHT/3])
    windowSurface.blit(mesg2,[WINDOWWIDTH/4+50, WINDOWHEIGHT/3+40])
    windowSurface.blit(mesg3,[WINDOWWIDTH/4+50, WINDOWHEIGHT/3+60])

#function that you can call to display the score to the screen#
def yourScore(score):
    msgScore = score_font.render('Score:' + str(score),True,YELLOW)
    windowSurface.blit(msgScore,[0,0])


#Define the snake class#
snakeSize = 10
class Snake:
    size = 10

    def __init__(self,rect,color,direc):
        self.rect = rect
        self.color = color
        self.direc = direc
#Draws the snake onto the screen#
def ourSnake(snakeSize,snakeList):
    for x in snakeList:
        pygame.draw.rect(windowSurface, WHITE,[x[0],x[1],snakeSize,snakeSize])



#We define the main game loop#
def main():
    
    gameClose = False   #value to check if the player has lost#
    player = Snake(pygame.Rect(WINDOWWIDTH/2,WINDOWHEIGHT/2,snakeSize,snakeSize),WHITE,U) #Build the players initial snake#
    SPEED = 10  #Speed of the snake#
    snakeLength = 1 #Initial length of the snake, to be incremented after contact with food#
    snakeList = []
        
    while True:
        #Creates a seperate loop that occurs after the game has been lost#
        while gameClose == True:
            windowSurface.fill(WHITE) 
            message('GAME OVER!','Press P to play','Press Q to quit',BLUE)
            pygame.display.update()
            #Defines which keys exit and which restarts the game#
            for event in pygame.event.get():
                if event.type == pygame.KEYDOWN:
                    if event.key == pygame.K_q:
                        pygame.quit()
                        sys.exit()
                    if event.key == pygame.K_p:
                        main()
        
        #Check for events#
        for event in pygame.event.get():
            #QUIT event type#
            if event.type == QUIT:
                    pygame.quit()
                    sys.exit()
            #Define wha the arrow and wasd keys do#
            if event.type == KEYDOWN:
                    if event.key == K_LEFT or event.key == K_a:
                        player.direc = L
                    if event.key == K_RIGHT or event.key == K_d:
                        player.direc = R
                    if event.key == K_UP or event.key == K_w:
                        player.direc = U  
                    if event.key == K_DOWN or event.key == K_s:
                        player.direc = D
                    if event.key == K_ESCAPE:
                        pygame.quit()
                        sys.exit()

        #Defines how the snake will move around the screen#
        #Also sets up bounds on the snake i.e. the edges of the screen#
        if player.direc == D and player.rect.bottom < WINDOWHEIGHT:
            player.rect.bottom += SPEED
        if player.direc == U and player.rect.top > 0:
            player.rect.top -= SPEED
        if player.direc == R and player.rect.right < WINDOWWIDTH:
            player.rect.right += SPEED
        if player.direc == L and player.rect.left > 0:
            player.rect.left -= SPEED

        #Draw the black background#
        windowSurface.fill(BLACK)

        #Draws foods onto the screen#
        for i in range(len(FOODS)):
            pygame.draw.rect(windowSurface,GREEN,FOODS[i])
            
        #Handles the collision of the sanke with the foods#
        #Removes the foods and appends a new food to the list the increments the snake length#
        for food in FOODS:
            if player.rect.colliderect(food):
                FOODS.remove(food)
                FOODS.append(pygame.Rect(random.randint(FOODSIZE,WINDOWWIDTH-2*FOODSIZE),
        random.randint(FOODSIZE,WINDOWHEIGHT-2*FOODSIZE),FOODSIZE,FOODSIZE))
                snakeLength += 1
        #Ends the game if the snake hits the boundaries of the screen#
        if (player.rect.bottom >= WINDOWHEIGHT or player.rect.top <= 0 or
            player.rect.left <= 0 or player.rect.right >= WINDOWWIDTH):
            gameClose = True

        #Prints the entire length of the snake#
        ####################################
        snakeHead = []
        snakeHead.append(player.rect.left)
        snakeHead.append(player.rect.top)
        snakeList.append(snakeHead)
        if len(snakeList) > snakeLength:
            del snakeList[0]
        ourSnake(snakeSize, snakeList)
        ####################################

        #Causes a game over if the snake runs into itself#
        for x in snakeList[:-1]:
            if x == snakeHead:
                gameClose = True

        #Displays your score to the screen#
        yourScore(snakeLength - 1)
        
        pygame.display.update()
        mainClock.tick(10)
        
    pygame.quit()
    sys.exit()


main()
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1 Answer 1

Reset to default
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Portability

My snake game runs

It does not run well for me. I tried it on 2 versions of Python 3 on Linux (with 2 different versions of Pygame installed). Perhaps I don't have the optimal environment for it, but this does point to portability issues.

When I run the code, it launches the GUI as expected. I initially see the snake moving for about one second, then I see "GAME OVER!". This is unexpected.

It gives me the option to play or quit, which is nice. When I press "P" to play, I see the snake head start moving, but it returns to the "GAME OVER!" screen very quickly.

Efficiency

These 5 separate if statements, starting with:

                if event.key == K_LEFT or event.key == K_a:
                    player.direc = L
                if event.key == K_RIGHT or event.key == K_d:

should be combined into a single if/elif statement:

                if event.key == K_LEFT or event.key == K_a:
                    player.direc = L
                elif event.key == K_RIGHT or event.key == K_d:

The event.key variable can only have one value, so the checks are mutually exclusive. This makes the code more efficient since you don't have to perform the 2nd check if the first is true, etc.

The same is true of these if statements:

    if player.direc == D and player.rect.bottom < WINDOWHEIGHT:
        player.rect.bottom += SPEED
    if player.direc == U and player.rect.top > 0:

Early escape

In this code, you loop through all the elements of the array:

    for x in snakeList[:-1]:
        if x == snakeHead:
            gameClose = True

You can make it more efficient by exiting the loop as soon as the condition is true using break:

    for x in snakeList[:-1]:
        if x == snakeHead:
            gameClose = True
            break

Documentation

Add a docstring to the top of the code to summarize the description of the code. It looks like the game supports 2 sets of keys:

  • The arrow keys
  • The A, W, S, D keys

This is mentioned in the PEP 8 style guide.

It would be helpful to mention this both in the docstring and displayed as instructions in the GUI.

For functions, it would be better to relpace comments like this:

#Draws the snake onto the screen#
def ourSnake(snakeSize,snakeList):

with docstrings:

def ourSnake(snakeSize,snakeList):
    """ Draws the snake onto the screen """

Naming

The guide also mentions using snake_case for variable and function names.

def our_snake(snake_size, snake_list):

Yes, it is pure coincidence that this style has "snake" in the name and your code is about snakes.

Simpler

There is no need for the intermediate variable i or the calls to length and range in the following loop:

    for i in range(len(FOODS)):
        pygame.draw.rect(windowSurface,GREEN,FOODS[i])

It is simpler as:

    for food in FOODS:
        pygame.draw.rect(windowSurface,GREEN,food)

Lint check

You could run code development tools to automatically find some style issues with your code.

For example, the ruff lint tool shows:

    `time` imported but unused
      |
      | import pygame,sys,random,time
    help: Remove unused import: `time`
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