snake.py

import pygame
import sys, random
from pygame.math import Vector2

class SNAKE:
    def __init__(self):
        self.body = [Vector2(5,10), Vector2(4,10), Vector2(3,10)]
        self.direction = Vector2(1,0)
        self.new_block = False

    def draw_snake(self):
        for block in self.body:
            #create a rect
            x_pos = int(block.x* cell_size)
            y_pos = int(block.y* cell_size)
            block_rect = pygame.Rect(x_pos, y_pos, cell_size, cell_size)
            
            #draw the rectangle
            pygame.draw.rect(screen, (183,111,122), block_rect)
        
    def move_snake(self):
        if self.new_block == True:
            body_copy = self.body[:]
            body_copy.insert(0, body_copy[0] + self.direction)
            self.body = body_copy[:]
            self.new_block = False
        else:
            body_copy = self.body[:-1]
            body_copy.insert(0, body_copy[0] + self.direction)
            self.body = body_copy[:]

    def add_block(self):
        self.new_block = True

class FRUIT:
    def __init__(self):
        self.randomize()
        # create an x and y position

    def draw_druit(self):
        fruit_rect = pygame.Rect(int(self.pos.x * cell_size) ,int(self.pos.y * cell_size) ,cell_size, cell_size)
        pygame.draw.rect(screen, ((126,166,114)), fruit_rect)
        #draw a square
    def randomize(self):
        self.x = random.randint(0, cell_number-1)
        self.y = random.randint(0, cell_number-1)
        self.pos = Vector2(self.x, self.y)

class MAIN:
    def __init__(self):
        self.snake = SNAKE()
        self.fruit = FRUIT()

    def update(self):
        self.snake.move_snake()
        self.check_collision()
        self.check_fail()

    def draw_elements(self):
        self.fruit.draw_druit()
        self.snake.draw_snake()

    def check_collision(self):
        if self.fruit.pos == self.snake.body[0]:
            # reposition fruit
            self.fruit.randomize()
            # add another block to the game
            self.snake.add_block()

    def check_fail(self):
        if not 0<= self.snake.body[0].x < cell_number or not 0<= self.snake.body[0].y < cell_number:
            self.game_over()
        
        for block in self.snake.body[1:]:
            if block == self.snake.body[0]:
                self.game_over()

    def game_over(self):
        pygame.quit()
        sys.exit()


pygame.init()
cell_size = 40
cell_number = 20
screen = pygame.display.set_mode((cell_number*cell_size,cell_number*cell_size))

#clock for controlling consistent speed of while loop across the devices
clock = pygame.time.Clock()



SCREEN_UPDATE = pygame.USEREVENT
pygame.time.set_timer(SCREEN_UPDATE, 150)

main_game = MAIN()

while True:
    #draw all our elements

    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            pygame.quit()
            sys.exit()

        # Snake Movement up - down - left - right:
        if event.type == SCREEN_UPDATE:
            main_game.update()
        if event.type ==pygame.KEYDOWN:
            if event.key == pygame.K_UP:
                if main_game.snake.direction.y !=1:
                    main_game.snake.direction = Vector2(0,-1)
            if event.key == pygame.K_DOWN:
                if main_game.snake.direction.y !=-1:
                    main_game.snake.direction = Vector2(0,1)
            if event.key == pygame.K_RIGHT:
                if main_game.snake.direction.x !=-1:
                    main_game.snake.direction = Vector2(1,0)
            if event.key == pygame.K_LEFT:
                if main_game.snake.direction.x !=1:
                    main_game.snake.direction = Vector2(-1,0)
    
    screen.fill((175,215,70)) #RGB tuple or color object
    main_game.draw_elements() #game draw elements
    pygame.display.update() #update the display
    clock.tick(60) #controls the speed of loop across the devices