Nepaklausīgā čūska

import pygame
import random

pygame.init()
pygame.display.set_caption("MySnake")
screen = pygame.display.set_mode((300, 400))
surface = pygame.Surface((300, 400))
screen.fill("white")
blue = (0,0,255)
red = (255,0,0)
white = (255,255,255)

# TODO: test game with various lengths
lengthOfSnake = 3
direction = "right"
gameOver = False
snake = []
routeX = []
routeY = []
score = 0
# TODO: test game with various speed settings
speed = 9  # sets speed of snake 0 - 9
myText = ""

# makes initial snake body
for i in range(lengthOfSnake):
    snake.append(pygame.draw.rect(screen,(255-i*5, 255-i*5, 0),[20*lengthOfSnake-i*20,0,20,20]))

# generate food coordinates
def setFoodLocation():
    # FIXME: food sometimes appears outside of the window
    # FIXME: food sometimes overlays body of the snake
    # FIXME: probably some other strange things happen... sometimes...
    global foodX, foodY
    foodX = random.randint(0, 17)*20 # generates number 0 - 280
    foodY = random.randint(0, 19)*20 # generates number 0 - 380
setFoodLocation()

# makes food
def makeFood():
    pygame.draw.rect(screen, white, [foodX, foodY, 20, 20])

# expands snake
def expandSnake():
    # FIXME: snake expands by two blocks instead of one, shouldn't be like that
    snake.append(pygame.draw.rect(screen,(180,180,0),[routeX[len(snake) - 1],routeY[len(snake) - 1],20,20]))

# checks collision with walls
def hitWall():
    # FIXME: snake goes out of field without losing
    if snake[0].x < 0 or snake[0].x >= 300 or snake[0].y < 0 or snake[0].y >= 500:
        gameIsOver()

# checks collision with body
def hitBody():
    for i in range(1, len(snake)):
        if snake[0].x == snake[i].x and snake[0].y == snake[i].y:
            # FIXME: snake doesn't die when hitting itself
            ...

# checks collision with food
def hitFood():
    # FIXME: score goes negative. why..?
    if foodX == snake[0].x and foodY == snake[0].y:
        global score 
        score -= 1
        setFoodLocation()
        expandSnake()
        expandSnake()

# updates score
def updateText(myText):
    pygame.display.set_caption(myText)

# stops snake, quits game
def gameIsOver():
    global gameOver
    gameOver = True
    updateText(myText = "Game Is Over")
    pygame.time.delay(1000)

# ***main loop***
while gameOver == False:
    for event in pygame.event.get():

        # X button closes game
        if event.type==pygame.QUIT:
            gameOver=True

        # defines key actions
        # FIXME: 'up' arrow doesn't work
        # FIXME: snake loses weight when going down.. drastic diet? o.O
        if event.type==pygame.KEYDOWN:
            if event.key==pygame.K_UP and direction != "down":
                direction = "uP"
            elif event.key==pygame.K_DOWN and direction != "up":
                direction = "down"
                snake.pop()
            elif event.key==pygame.K_RIGHT and direction != "left":
                direction = "left"
            elif event.key==pygame.K_LEFT and direction != "right":
                direction = "right"

    # saves route in lists, lets snake to follow itself
    for i in range(len(snake)):
        routeX.insert(i, snake[i].x)
        routeY.insert(i, snake[i].y)

    # moves head according to commands
    # FIXME: background goes crazy, should be solid all the time
    screen.fill(random.choice(["green", "black", "blue"]))
    if direction == "up":
        snake[0] = pygame.draw.rect(screen,(255,255,0),[routeX[0],routeY[0]-20,20,20])

    # FIXME: 'down' direction has bug, snake collapses when going down
    elif direction == "down":
        snake[0] = pygame.draw.rect(screen,(255,255,0),[routeX[0],routeY[0]+30,20,20])
    # FIXME: snake dies when opposite direction activated
    elif direction == "right":
        snake[0] = pygame.draw.rect(screen,(255,255,0),[routeX[0]+20,routeY[0],20,20])
    elif direction == "left":
        snake[0] = pygame.draw.rect(screen,(255,255,0),[routeX[0]-20,routeY[0],20,20])

    # moves body
    for i in range(1, len(snake)):
        snake[i] = pygame.draw.rect(screen, (180, 180, 0),[routeX[i - 1],routeY[i - 1],20,20])

    hitBody()
    hitWall()

    # FIXME: snake doesn't catch food, something is missing here \_(o.O_/

    makeFood()
    updateText(myText = "score " + str(score))

    pygame.display.update()  # rerenders screen
    pygame.time.delay(1000-speed*100)  # movement delay

pygame.quit()