The Complete Python Snake Game Code: A Step-by-Step Guide

In this blog post, we’ll explore the complete code for a Python-based Snake game. We’ll break down the code into manageable sections, providing a step-by-step guide to help you understand how each part works and how they all fit together.

Game Overview

The Snake game is a classic arcade game where the player controls a snake that moves around a grid, eating food to grow longer. The game ends when the snake collides with itself or the edges of the game board.

Code Structure

The code for the Snake game can be divided into several sections:

1. Initialization: Set up the game board, snake, and food.
2. Game Loop: Continuously update the game state based on user input and check for collisions.
3. Drawing Functions: Render the game board, snake, and food on the screen.
4. Input Handling: Process keyboard input to move the snake.
5. Collision Detection: Check if the snake has collided with itself or the game board edges.

Code Implementation

Here’s a simplified version of the complete code for the Snake game:

pythonimport pygame
import random

# Initialize pygame
pygame.init()

# Define colors
WHITE = (255, 255, 255)
RED = (255, 0, 0)
GREEN = (0, 255, 0)

# Set up the game window
WIDTH, HEIGHT = 400, 400
WIN = pygame.display.set_mode((WIDTH, HEIGHT))
pygame.display.set_caption("Snake Game")

# Define the snake
SNAKE_SIZE = 20
SNAKE_SPEED = 15
snake = [(WIDTH // 2, HEIGHT // 2)]
snake_direction = [0, SNAKE_SPEED]

# Define the food
food = None
def generate_food():
    global food
    while True:
        x = random.randint(0, (WIDTH // SNAKE_SIZE) - 1) * SNAKE_SIZE
        y = random.randint(0, (HEIGHT // SNAKE_SIZE) - 1) * SNAKE_SIZE
        if (x, y) not in snake:
            food = (x, y)
            break

generate_food()

# Game loop
running = True
clock = pygame.time.Clock()

while running:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False
        elif event.type == pygame.KEYDOWN:
            if event.key == pygame.K_UP and snake_direction[1] == 0:
                snake_direction = [0, -SNAKE_SPEED]
            elif event.key == pygame.K_DOWN and snake_direction[1] == 0:
                snake_direction = [0, SNAKE_SPEED]
            elif event.key == pygame.K_LEFT and snake_direction[0] == 0:
                snake_direction = [-SNAKE_SPEED, 0]
            elif event.key == pygame.K_RIGHT and snake_direction[0] == 0:
                snake_direction = [SNAKE_SPEED, 0]

    # Move the snake
    head = snake[0]
    snake.insert(0, (head[0] + snake_direction[0], head[1] + snake_direction[1]))

    # Check for collisions
    if snake[0] in snake[1:]:
        running = False
    if snake[0][0] < 0 or snake[0][0] >= WIDTH or snake[0][1] < 0 or snake[0][1] >= HEIGHT:
        running = False

    # Check if snake has eaten the food
    if snake[0] == food:
        generate_food()
    else:
        snake.pop()

    # Draw the game
    WIN.fill(WHITE)
    pygame.draw.rect(WIN, GREEN, (food[0], food[1], SNAKE_SIZE, SNAKE_SIZE))
    for segment in snake:
        pygame.draw.rect(WIN, RED, (segment[0], segment[1], SNAKE_SIZE, SNAKE_SIZE))
    pygame.display.update()

    # Maintain game speed
    clock.tick(15)