Revisions to Python snake game with pygame - Code Review Stack Exchange

Made `check_death` more readable and you can append a copy of the last snake part when it eats.

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edited Apr 25, 2017 at 18:16

skrx

431
4
8

import sys
import random

import pygame
from pygame.math import Vector2


pygame.init()

display_width = 800
display_height = 600
game_display = pygame.display.set_mode((display_width, display_height))
DISPLAY_RECT = pygame.Rect(0, 0, display_width, display_height)

WHITE = pygame.Color('white')
BLACK = pygame.Color('black')
TEAL = pygame.Color(0, 128, 128)


def update_snake(snake, new_pos):
    for part in snake:
        part.topleft, new_pos = new_pos, part.topleft


def check_death(snake):
    returntouched_body (= any(snake[0].colliderect(part) for part in snake[1:])
    in_game_area = DISPLAY_RECT.contains(snake[0])
    return touched_body or not DISPLAY_RECT.contains(snake[0]))in_game_area


def main():
    clock = pygame.time.Clock()
    score = 60
    size = 10
    snake = [pygame.Rect(20, y, size, size) for y in range(20, 171, 10)]
    food = pygame.Rect(
        random.randrange(0, display_width, 10),
        random.randrange(0, display_height, 10),
        size, size)
    pos = Vector2(snake[0].topleft)
    vel = Vector2(10, 0)

    running = True
    while running:
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                running = False
            if event.type == pygame.KEYDOWN:
                if event.key == pygame.K_a:
                    vel = Vector2(-10, 0)
                elif event.key == pygame.K_d:
                    vel = Vector2(10, 0)
                elif event.key == pygame.K_w:
                    vel = Vector2(0, -10)
                elif event.key == pygame.K_s:
                    vel = Vector2(0, 10)
                elif event.key == pygame.K_c:
                    vel = Vector2(0, 0)

        pos += vel
        update_snake(snake, pos)

        if snake[0].colliderect(food):
            score += 10
            food.topleft = (random.randrange(0, display_width, 10),
                            random.randrange(0, display_height, 10))
            snake.append(pygame.Rect(snake[-1].x, snake[-1].y, 10, 10copy())
            print(len(snake), score)

        if check_death(snake):
            running = False

        game_display.fill(WHITE)
        pygame.draw.rect(game_display, BLACK, food)
        for rect in snake:
            pygame.draw.rect(game_display, TEAL, rect)

        pygame.display.update()
        pygame.time.wait(35)
        clock.tick(60)


if __name__ == '__main__':
    main()
    pygame.quit()
    sys.exit()

import sys
import random

import pygame
from pygame.math import Vector2


pygame.init()

display_width = 800
display_height = 600
game_display = pygame.display.set_mode((display_width, display_height))
DISPLAY_RECT = pygame.Rect(0, 0, display_width, display_height)

WHITE = pygame.Color('white')
BLACK = pygame.Color('black')
TEAL = pygame.Color(0, 128, 128)


def update_snake(snake, new_pos):
    for part in snake:
        part.topleft, new_pos = new_pos, part.topleft


def check_death(snake):
    return (any(snake[0].colliderect(part) for part in snake[1:])
            or not DISPLAY_RECT.contains(snake[0]))


def main():
    clock = pygame.time.Clock()
    score = 60
    size = 10
    snake = [pygame.Rect(20, y, size, size) for y in range(20, 171, 10)]
    food = pygame.Rect(
        random.randrange(0, display_width, 10),
        random.randrange(0, display_height, 10),
        size, size)
    pos = Vector2(snake[0].topleft)
    vel = Vector2(10, 0)

    running = True
    while running:
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                running = False
            if event.type == pygame.KEYDOWN:
                if event.key == pygame.K_a:
                    vel = Vector2(-10, 0)
                elif event.key == pygame.K_d:
                    vel = Vector2(10, 0)
                elif event.key == pygame.K_w:
                    vel = Vector2(0, -10)
                elif event.key == pygame.K_s:
                    vel = Vector2(0, 10)
                elif event.key == pygame.K_c:
                    vel = Vector2(0, 0)

        pos += vel
        update_snake(snake, pos)

        if snake[0].colliderect(food):
            score += 10
            food.topleft = (random.randrange(0, display_width, 10),
                            random.randrange(0, display_height, 10))
            snake.append(pygame.Rect(snake[-1].x, snake[-1].y, 10, 10))
            print(len(snake), score)

        if check_death(snake):
            running = False

        game_display.fill(WHITE)
        pygame.draw.rect(game_display, BLACK, food)
        for rect in snake:
            pygame.draw.rect(game_display, TEAL, rect)

        pygame.display.update()
        pygame.time.wait(35)
        clock.tick(60)


if __name__ == '__main__':
    main()
    pygame.quit()
    sys.exit()

import sys
import random

import pygame
from pygame.math import Vector2


pygame.init()

display_width = 800
display_height = 600
game_display = pygame.display.set_mode((display_width, display_height))
DISPLAY_RECT = pygame.Rect(0, 0, display_width, display_height)

WHITE = pygame.Color('white')
BLACK = pygame.Color('black')
TEAL = pygame.Color(0, 128, 128)


def update_snake(snake, new_pos):
    for part in snake:
        part.topleft, new_pos = new_pos, part.topleft


def check_death(snake):
    touched_body = any(snake[0].colliderect(part) for part in snake[1:])
    in_game_area = DISPLAY_RECT.contains(snake[0])
    return touched_body or not in_game_area


def main():
    clock = pygame.time.Clock()
    score = 60
    size = 10
    snake = [pygame.Rect(20, y, size, size) for y in range(20, 171, 10)]
    food = pygame.Rect(
        random.randrange(0, display_width, 10),
        random.randrange(0, display_height, 10),
        size, size)
    pos = Vector2(snake[0].topleft)
    vel = Vector2(10, 0)

    running = True
    while running:
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                running = False
            if event.type == pygame.KEYDOWN:
                if event.key == pygame.K_a:
                    vel = Vector2(-10, 0)
                elif event.key == pygame.K_d:
                    vel = Vector2(10, 0)
                elif event.key == pygame.K_w:
                    vel = Vector2(0, -10)
                elif event.key == pygame.K_s:
                    vel = Vector2(0, 10)
                elif event.key == pygame.K_c:
                    vel = Vector2(0, 0)

        pos += vel
        update_snake(snake, pos)

        if snake[0].colliderect(food):
            score += 10
            food.topleft = (random.randrange(0, display_width, 10),
                            random.randrange(0, display_height, 10))
            snake.append(snake[-1].copy())
            print(len(snake), score)

        if check_death(snake):
            running = False

        game_display.fill(WHITE)
        pygame.draw.rect(game_display, BLACK, food)
        for rect in snake:
            pygame.draw.rect(game_display, TEAL, rect)

        pygame.display.update()
        pygame.time.wait(35)
        clock.tick(60)


if __name__ == '__main__':
    main()
    pygame.quit()
    sys.exit()

running = not check_death prevented the closing of the game.

Source Link

edited Apr 25, 2017 at 0:53

skrx

431
4
8

import sys
import random

import pygame
from pygame.math import Vector2


pygame.init()

display_width = 800
display_height = 600
game_display = pygame.display.set_mode((display_width, display_height))
DISPLAY_RECT = pygame.Rect(0, 0, display_width, display_height)

WHITE = pygame.Color('white')
BLACK = pygame.Color('black')
TEAL = pygame.Color(0, 128, 128)


def update_snake(snake, new_pos):
    for part in snake:
        part.topleft, new_pos = new_pos, part.topleft


def check_death(snake):
    return (any(snake[0].colliderect(part) for part in snake[1:])
            or not DISPLAY_RECT.contains(snake[0]))


def main():
    clock = pygame.time.Clock()
    score = 60
    size = 10
    snake = [pygame.Rect(20, y, size, size) for y in range(20, 171, 10)]
    food = pygame.Rect(
        random.randrange(0, display_width, 10),
        random.randrange(0, display_height, 10),
        size, size)
    pos = Vector2(snake[0].topleft)
    vel = Vector2(10, 0)

    running = True
    while running:
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                running = False
            if event.type == pygame.KEYDOWN:
                if event.key == pygame.K_a:
                    vel = Vector2(-10, 0)
                elif event.key == pygame.K_d:
                    vel = Vector2(10, 0)
                elif event.key == pygame.K_w:
                    vel = Vector2(0, -10)
                elif event.key == pygame.K_s:
                    vel = Vector2(0, 10)
                elif event.key == pygame.K_c:
                    vel = Vector2(0, 0)

        pos += vel
        update_snake(snake, pos)

        if snake[0].colliderect(food):
            score += 10
            food.topleft = (random.randrange(0, display_width, 10),
                            random.randrange(0, display_height, 10))
            snake.append(pygame.Rect(snake[-1].x, snake[-1].y, 10, 10))
            print(len(snake), score)

        running = notif check_death(snake):
            running = False

        game_display.fill(WHITE)
 
        pygame.draw.rect(game_display, BLACK, food)
        for rect in snake:
            pygame.draw.rect(game_display, TEAL, rect)

        pygame.display.update()
        pygame.time.wait(35)
        clock.tick(60)


if __name__ == '__main__':
    main()
    pygame.quit()
    sys.exit()

import sys
import random

import pygame
from pygame.math import Vector2


pygame.init()

display_width = 800
display_height = 600
game_display = pygame.display.set_mode((display_width, display_height))
DISPLAY_RECT = pygame.Rect(0, 0, display_width, display_height)

WHITE = pygame.Color('white')
BLACK = pygame.Color('black')
TEAL = pygame.Color(0, 128, 128)


def update_snake(snake, new_pos):
    for part in snake:
        part.topleft, new_pos = new_pos, part.topleft


def check_death(snake):
    return (any(snake[0].colliderect(part) for part in snake[1:])
            or not DISPLAY_RECT.contains(snake[0]))


def main():
    clock = pygame.time.Clock()
    score = 60
    size = 10
    snake = [pygame.Rect(20, y, size, size) for y in range(20, 171, 10)]
    food = pygame.Rect(
        random.randrange(0, display_width, 10),
        random.randrange(0, display_height, 10),
        size, size)
    pos = Vector2(snake[0].topleft)
    vel = Vector2(10, 0)

    running = True
    while running:
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                running = False
            if event.type == pygame.KEYDOWN:
                if event.key == pygame.K_a:
                    vel = Vector2(-10, 0)
                elif event.key == pygame.K_d:
                    vel = Vector2(10, 0)
                elif event.key == pygame.K_w:
                    vel = Vector2(0, -10)
                elif event.key == pygame.K_s:
                    vel = Vector2(0, 10)
                elif event.key == pygame.K_c:
                    vel = Vector2(0, 0)

        pos += vel
        update_snake(snake, pos)

        if snake[0].colliderect(food):
            score += 10
            food.topleft = (random.randrange(0, display_width, 10),
                            random.randrange(0, display_height, 10))
            snake.append(pygame.Rect(snake[-1].x, snake[-1].y, 10, 10))
            print(len(snake), score)

        running = not check_death(snake)
        game_display.fill(WHITE)
 
        pygame.draw.rect(game_display, BLACK, food)
        for rect in snake:
            pygame.draw.rect(game_display, TEAL, rect)

        pygame.display.update()
        pygame.time.wait(35)
        clock.tick(60)


if __name__ == '__main__':
    main()
    pygame.quit()
    sys.exit()

import sys
import random

import pygame
from pygame.math import Vector2


pygame.init()

display_width = 800
display_height = 600
game_display = pygame.display.set_mode((display_width, display_height))
DISPLAY_RECT = pygame.Rect(0, 0, display_width, display_height)

WHITE = pygame.Color('white')
BLACK = pygame.Color('black')
TEAL = pygame.Color(0, 128, 128)


def update_snake(snake, new_pos):
    for part in snake:
        part.topleft, new_pos = new_pos, part.topleft


def check_death(snake):
    return (any(snake[0].colliderect(part) for part in snake[1:])
            or not DISPLAY_RECT.contains(snake[0]))


def main():
    clock = pygame.time.Clock()
    score = 60
    size = 10
    snake = [pygame.Rect(20, y, size, size) for y in range(20, 171, 10)]
    food = pygame.Rect(
        random.randrange(0, display_width, 10),
        random.randrange(0, display_height, 10),
        size, size)
    pos = Vector2(snake[0].topleft)
    vel = Vector2(10, 0)

    running = True
    while running:
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                running = False
            if event.type == pygame.KEYDOWN:
                if event.key == pygame.K_a:
                    vel = Vector2(-10, 0)
                elif event.key == pygame.K_d:
                    vel = Vector2(10, 0)
                elif event.key == pygame.K_w:
                    vel = Vector2(0, -10)
                elif event.key == pygame.K_s:
                    vel = Vector2(0, 10)
                elif event.key == pygame.K_c:
                    vel = Vector2(0, 0)

        pos += vel
        update_snake(snake, pos)

        if snake[0].colliderect(food):
            score += 10
            food.topleft = (random.randrange(0, display_width, 10),
                            random.randrange(0, display_height, 10))
            snake.append(pygame.Rect(snake[-1].x, snake[-1].y, 10, 10))
            print(len(snake), score)

        if check_death(snake):
            running = False

        game_display.fill(WHITE)
        pygame.draw.rect(game_display, BLACK, food)
        for rect in snake:
            pygame.draw.rect(game_display, TEAL, rect)

        pygame.display.update()
        pygame.time.wait(35)
        clock.tick(60)


if __name__ == '__main__':
    main()
    pygame.quit()
    sys.exit()

Source Link

answered Apr 25, 2017 at 0:45

skrx

431
4
8

I suggest to use pygame.Rects and pygame.math.Vector2 to make your life easier and the code cleaner and more beautiful. The snake would be a list of rects and the velocity and position vectors. Rects have a colliderect method with which you can see if it collides with another rect (e.g. the snake head with the body or the food rect).

In the update_snake method you can iterate over the snake parts (rects) and then just set the part's topleft attribute to the new position and the new pos to the previous position of the part at the same time (with the help of tuple unpacking). BTW, iterate over the list directly for part in snake: instead of for i in range(len(snake)):.

In the check_death function you can use a rect with the size of the display and then check if it contains the head rect of the snake DISPLAY_RECT.contains(snake[0]). And for collisions with the body any(snake[0].colliderect(part) for part in snake[1:]).

import sys
import random

import pygame
from pygame.math import Vector2


pygame.init()

display_width = 800
display_height = 600
game_display = pygame.display.set_mode((display_width, display_height))
DISPLAY_RECT = pygame.Rect(0, 0, display_width, display_height)

WHITE = pygame.Color('white')
BLACK = pygame.Color('black')
TEAL = pygame.Color(0, 128, 128)


def update_snake(snake, new_pos):
    for part in snake:
        part.topleft, new_pos = new_pos, part.topleft


def check_death(snake):
    return (any(snake[0].colliderect(part) for part in snake[1:])
            or not DISPLAY_RECT.contains(snake[0]))


def main():
    clock = pygame.time.Clock()
    score = 60
    size = 10
    snake = [pygame.Rect(20, y, size, size) for y in range(20, 171, 10)]
    food = pygame.Rect(
        random.randrange(0, display_width, 10),
        random.randrange(0, display_height, 10),
        size, size)
    pos = Vector2(snake[0].topleft)
    vel = Vector2(10, 0)

    running = True
    while running:
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                running = False
            if event.type == pygame.KEYDOWN:
                if event.key == pygame.K_a:
                    vel = Vector2(-10, 0)
                elif event.key == pygame.K_d:
                    vel = Vector2(10, 0)
                elif event.key == pygame.K_w:
                    vel = Vector2(0, -10)
                elif event.key == pygame.K_s:
                    vel = Vector2(0, 10)
                elif event.key == pygame.K_c:
                    vel = Vector2(0, 0)

        pos += vel
        update_snake(snake, pos)

        if snake[0].colliderect(food):
            score += 10
            food.topleft = (random.randrange(0, display_width, 10),
                            random.randrange(0, display_height, 10))
            snake.append(pygame.Rect(snake[-1].x, snake[-1].y, 10, 10))
            print(len(snake), score)

        running = not check_death(snake)
        game_display.fill(WHITE)

        pygame.draw.rect(game_display, BLACK, food)
        for rect in snake:
            pygame.draw.rect(game_display, TEAL, rect)

        pygame.display.update()
        pygame.time.wait(35)
        clock.tick(60)


if __name__ == '__main__':
    main()
    pygame.quit()
    sys.exit()

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