Jump to content
  • Advertisement
Sign in to follow this  

PyclassicS - Snake Game (Code Review)

This topic is 2055 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

If you intended to correct an error in the post then please contact us.

Recommended Posts

I've written my second game. It's my open-source implementation of the classic "Snake" concept. It has "speed" and "bounds" options.

There's a windows binary inside the "dist" folder. (If you're a Linux user, you just need to have Python and Pygame installed and run main.py directly). (If you're curious, here's my first one, written in C with SDL2).

Download link on Sourceforge:

Entire code:



Copyright (C) <2014>  <Ericson Willians.>

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.

Game written by Ericson Willians, a brazilian composer and programmer.

CONTACT: ericsonwrp@gmail.com
AS A COMPOSER: https://soundcloud.com/r-p-ericson-willians
YOUTUBE CHANNEL: http://www.youtube.com/user/poisonewein


__author__ = 'EricsonWillians'

from pygame import *
from random import *

init() #Pygame Init Function

speed = 16 # An arbitrary speed value to be used in clock.tick()
squareSize = 16 # The default size of every game element (Each snake piece, and the food).
screenSize = squareSize*48 # The size of the screen: 768 by 768 pixels (16 based).
screen = display.set_mode((screenSize, screenSize)) # Pygame screen-creating function.
gameFont = font.SysFont("helvetica", 16, True)
creditFont = font.SysFont("helvetica", 10, True)

done = False # Variable to handle the game's main loop.
pause = False # Variable to handle the pause option (We'll draw and deal with everything IF pause equals to false).
bounds = True # Enable "death" when outside the screen's boundaries.
fullscreen = False
clock = time.Clock() # Creating an instance of pygame.time.Clock() class to deal with "tick" method later on.
colors = {"BG": (0, 0, 0), "GAME": (255, 255, 255), "ON": (0, 255, 0), "OFF": (255, 0, 0)} # BG = BLACK, GAME = WHITE.
directions = ["NORTH", "SOUTH", "WEST", "EAST"] # Directions.
food = [randrange(0, 48), randrange(0, 48)] # Food's random initial coordinates.
snakeDirection = directions[0]
gridIndex = [] # The list to store every "grid index".
realPos = [] # The real position of each "grid index" in the screen, in terms of pixels.
# The grid has 48 squares of 16 by 16 pixels. I'll use the same indexes for the Y axis (The whole screen is a square).
for i in range(0, 48):
    gridIndex.append(i) # Stores the 48 index (0 to 47).
    realPos.append(i*16) # Stores the actual positions in the screen (0 to 752).
gridKeys = dict(zip(gridIndex, realPos)) # Transforms every index into a key, with its corresponding real position.
score = 0
snakeLength = [[24, 24],[24, 23]]

def drawSnake():
        # It loops through snakeLength list, and then I access each individual x and y keys inside each list (Each "snake piece").
    for i in snakeLength:
            draw.rect(screen, colors.get("GAME"), (gridKeys.get(i[0]), gridKeys.get(i[1]), squareSize, squareSize))

def drawBackground():
    # The default screen color is already black, but it's necessary to REALLY DRAW each "ground" in order not to make a "tron game".
    for i in range(0, 48): # The principle here is pretty straight-foward: For each collumn (48),
        for j in range(0, 48): # draw 48 16 by 16 squares (Filling the entire 768 by 768 screen).
            draw.rect(screen, colors.get("BG"), (i*16, j*16, squareSize, squareSize))

# The "updateGame()" procedure is called inside the main loop.
# It's more organized than just throwing code inside the game loop.

def updateGame():

    def respawnFood():
        food[0] = randrange(0, 48)
        food[1] = randrange(0, 48)

    # Now things get quite complicated. Here's the snake-movement part, a beast quite hard to grasp at first.
    # Basically, the snake is just a FIFO-QUEUE.

    def default():
        global score
        del snakeLength[:]
        score = 0
        print "GAME OVER!\n"*100

    def moveSnake():
        global score # Avoiding python scope problems.
        snakeLength.pop() # "pop()" removes the last list-element and returns it (But I don't use the returned element (It falls into the Void.))
        next = snakeLength[0] # Here I create a variable to store the very first snake index (List with x and y coordinates).
        drawBackground() # Draws the background at each frame.
        draw.rect(screen, colors.get("GAME"), (gridKeys.get(food[0]), gridKeys.get(food[1]), squareSize, squareSize)) # It draws the food.
        drawSnake() # Draws the snake after the background at each frame.
        print "Positions: " + str(snakeLength) # Print the snake for debugging purposes.
        if snakeDirection == "NORTH": # If the snake's current direction equals to NORTH:
            next = (next[0], next[1]-1) # That first index of the snake has it's y coordinate subtracted by 1.
            if ((next[0] == food[0]) and (next[1] == food[1])): # If the snake pos is equal to the food pos.
                snakeLength.append((snakeLength[len(snakeLength)-1][0], snakeLength[len(snakeLength)-1][1]-1)) # Append a new tuple-snake-piece in front of the last.
                score += 1
        elif snakeDirection == "SOUTH": # The same for the rest...
            next = (next[0], next[1]+1)
            if ((next[0] == food[0]) and (next[1] == food[1])):
                snakeLength.append((snakeLength[len(snakeLength)-1][0], snakeLength[len(snakeLength)-1][1]+1))
                score += 1
        elif snakeDirection == "WEST":
            next = (next[0]-1, next[1])
            if ((next[0] == food[0]) and (next[1] == food[1])):
                snakeLength.append((snakeLength[len(snakeLength)-1][0]-1, snakeLength[len(snakeLength)-1][1]))
                score += 1
        elif snakeDirection == "EAST":
            next = (next[0]+1, next[1])
            if ((next[0] == food[0]) and (next[1] == food[1])):
                snakeLength.append((snakeLength[len(snakeLength)-1][0]+1, snakeLength[len(snakeLength)-1][1]))
                score += 1
        # If the head of the snake gets off-screen, it defaults the game.
        if bounds == True:
            if next[1] < 0:
            elif next[1] > 47:
            elif next[0] < 0:
            elif next[0] > 47:
        # This part defaults the game if the snake collides with its own tail.
            if len(snakeLength) > 2:
                for i in snakeLength:
                    if ((next[0] == i[0]) and (next[1] == i[1])):
        snakeLength.insert(0, next) # It inserts to the first position of the snake that very old-first one, forcing it to the new position.

    moveSnake() # I've made this procedure just for the "moveSnake()" name. It's easier to understand than throwing movement-code up there at random.

def keyPressed(inputKey): # Just a function to deal with inputs more efficiently.
    keysPressed = key.get_pressed()
    if keysPressed[inputKey]:
        return True
        return False

while not done: # WHILE NOT DONE... While done equals to that False up there.
    for e in event.get(): # For each event in whatever-that-pygame-function-returns (A list, probably).
        if e.type == QUIT or keyPressed(K_ESCAPE): # If that "e" variable equals to pygame QUIT (Some inner/default value) or to the escape key.
            done = True # FINISH THE LOOP! (For it runs only while done is equal to that False up there).
        if keyPressed(K_p) and pause == False: # Pretty straight-foward pause logic.
            pause = True
            print "Paused Game."
        elif keyPressed(K_p) and pause == True:
            pause = False
            print "Game resumed..."
        if keyPressed(K_F10): # Enter fullscreen.
            screen = display.set_mode((screenSize, screenSize), FULLSCREEN)
            fullscreen = True
        if keyPressed(K_F11): # Exit fullscreen.
            screen = display.set_mode((screenSize, screenSize))
            fullScreen = False
        # It changes the direction (What changes the snakeDirection up there)
        if keyPressed(K_UP) or keyPressed(K_w):
            snakeDirection = directions[0]
        if keyPressed(K_DOWN) or keyPressed(K_s):
            snakeDirection = directions[1]
        if keyPressed(K_LEFT) or keyPressed(K_a):
            snakeDirection = directions[2]
        if keyPressed(K_RIGHT) or keyPressed(K_d):
            snakeDirection = directions[3]
        if keyPressed(K_KP_MINUS):
            speed /= 2
        if keyPressed(K_KP_PLUS):
            speed *= 2
        if (keyPressed(K_b) and (bounds == True)):
            bounds = False
        elif (keyPressed(K_b) and (bounds == False)):
            bounds = True

    if  pause == False:
            updateGame() # Much better than all that code down here, isn't it?
            # The default procedure just clears the snakeLength list. It's here that it is set to its original value.
            # When a TypeError is found.
            if bounds == True:
                snakeLength = [[24, 24],[24, 23]]

    scoreText = gameFont.render("Score: " + str(score), True, colors.get("GAME"))
    speedText = gameFont.render("Speed: " + str(speed), True, colors.get("GAME"))
    if bounds == True:
        boundsText = gameFont.render("Bounds: ON", True, colors.get("ON"))
        screen.blit(boundsText, (10, 50))
    elif bounds == False:
        boundsText = gameFont.render("Bounds: OFF", True, colors.get("OFF"))
        coordinates = gameFont.render("x: " + str(snakeLength[len(snakeLength)-1][0]) + " " + "y: " + str(snakeLength[len(snakeLength)-1][1]), True, colors.get("OFF"))
        screen.blit(boundsText, (10, 50))
        screen.blit(coordinates, (690, 10))
    if fullscreen == False:
        fullscreenText = gameFont.render("Fullscreen: OFF", True, colors.get("OFF"))
        screen.blit(fullscreenText, (10, 70))
    elif fullscreen == True:
        fullscreenText = gameFont.render("Fullscreen: ON", True, colors.get("ON"))
        screen.blit(fullscreenText, (10, 70))
    keysText = creditFont.render("Keys: ARROWS, WASD, KP +-, B, F10, F11.", True, colors.get("GAME"))
    creditText = creditFont.render("Developed by Ericson Willians.", True, colors.get("GAME"))
    screen.blit(scoreText, (10, 10))
    screen.blit(speedText, (10, 30))
    screen.blit(keysText, (10, 750))
    screen.blit(creditText, (620, 750))
    display.update() # Pygame default display-thing.
    display.flip() # It updates the whole thing at each frame of the loop, or something like that.
    clock.tick(speed) # The pygame speed, or something like that.

print "Exiting..."
quit() # When done is equal to True, the program reaches this area (It closes).
Edited by EricsonWillians

Share this post

Link to post
Share on other sites
Sign in to follow this  

  • Advertisement

Important Information

By using GameDev.net, you agree to our community Guidelines, Terms of Use, and Privacy Policy.

GameDev.net is your game development community. Create an account for your GameDev Portfolio and participate in the largest developer community in the games industry.

Sign me up!