保存记录

本课属于 Coddy Pygame 学习旅程的“游戏规则”单元。第 20 课，共 30 课。

关闭游戏后，best 就消失了：变量只在程序运行时存在。要把数字留到下次使用，就把它写入文件。

with open("highscore.txt", "w") as file:
    file.write(str(best))

open(..., "w") 会打开文件以便写入。如果文件不存在，就会创建文件；如果文件已存在，就会清空文件，因此文件中始终只有一个数字。write 接收文本，所以要先用 str(best) 把数字转换成文本。with 代码块结束时会关闭文件，因此写入的内容都会保存。

文件名中没有文件夹路径，因此文件会创建在程序运行所在的文件夹中。在你的电脑上，从 main.py 所在的文件夹运行它，highscore.txt 就会出现在它旁边，并一直保留在那里。

在浏览器中，游戏文件保存在网页的内存里：再玩一次时，文件仍然存在，但重新加载网页后，文件就不见了。

挑战

中等

将最高分保存到文件中，这样游戏结束后它也会保留下来。

游戏结束时，在更新 best 后，在 with 代码块中用 "w" 打开 highscore.txt。
将 str(best) 写入文件。

按“开始”并输掉游戏：最高分会保存到 highscore.txt 中。然后按“检查”。

亲手试试

import random
import pygame

pygame.init()
screen = pygame.display.set_mode((480, 360))
pygame.display.set_caption("Meteor Dodge")
clock = pygame.time.Clock()
heart = pygame.image.load("assets/images/heart.png").convert_alpha()
heart_empty = pygame.image.load("assets/images/heart_empty.png").convert_alpha()
font = pygame.font.Font("assets/fonts/pixel.ttf", 24)
big_font = pygame.font.Font("assets/fonts/pixel.ttf", 48)
WHITE = (240, 240, 240)
PLATE = (60, 60, 90)
POINT = pygame.USEREVENT + 1
SPAWN = pygame.USEREVENT + 2


def reset():
    global player, rocks, score, lives
    player = pygame.Rect(220, 300, 40, 40)
    rocks = []
    score = 0
    lives = 3
    pygame.time.set_timer(POINT, 1000)
    pygame.time.set_timer(SPAWN, 800)


def draw_menu():
    screen.fill((30, 30, 46))
    title = big_font.render("Meteor Dodge", True, WHITE)
    title_rect = title.get_rect(center=(240, 140))
    pygame.draw.rect(screen, PLATE, title_rect.inflate(24, 12))
    screen.blit(title, title_rect)
    hint = font.render("Press Enter to play", True, WHITE)
    screen.blit(hint, hint.get_rect(center=(240, 200)))


def draw_game():
    screen.fill((30, 30, 46))
    pygame.draw.rect(screen, (255, 196, 0), player)
    for rock in rocks:
        pygame.draw.rect(screen, (235, 80, 80), rock)
    score_text = font.render(f"{score:05}", True, WHITE)
    score_rect = score_text.get_rect(topright=(470, 10))
    pygame.draw.rect(screen, PLATE, score_rect.inflate(12, 8))
    screen.blit(score_text, score_rect)
    for i in range(3):
        if i < lives:
            screen.blit(heart, (10 + i * 40, 10))
        else:
            screen.blit(heart_empty, (10 + i * 40, 10))


def play_frame():
    global rocks, lives, state, best
    keys = pygame.key.get_pressed()
    if keys[pygame.K_LEFT]:
        player.x -= 6
    if keys[pygame.K_RIGHT]:
        player.x += 6
    player.clamp_ip(screen.get_rect())

    kept = []
    for rock in rocks:
        rock.y += 3
        if rock.colliderect(player):
            lives -= 1
        elif rock.top <= 360:
            kept.append(rock)
    rocks = kept
    if lives <= 0:
        state = "over"
        best = max(best, score)
    draw_game()


def draw_over():
    draw_game()
    message = big_font.render("Game over", True, WHITE)
    screen.blit(message, message.get_rect(center=(240, 160)))
    hint = font.render("Press R to play again", True, WHITE)
    screen.blit(hint, hint.get_rect(center=(240, 200)))
    best_text = font.render(f"Best: {best}", True, WHITE)
    screen.blit(best_text, best_text.get_rect(center=(240, 240)))


reset()
state = "menu"
best = 0

running = True
while running:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False
        if event.type == POINT and state == "play":
            score += 1
        if event.type == SPAWN and state == "play":
            rocks.append(pygame.Rect(random.randint(0, 456), -24, 24, 24))
        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_RETURN and state == "menu":
                reset()
                state = "play"
            elif event.key == pygame.K_r and state == "over":
                reset()
                state = "play"

    if state == "menu":
        draw_menu()
    elif state == "play":
        play_frame()
    else:
        draw_over()
    pygame.display.flip()
    clock.tick(60)

pygame.quit()

游戏规则中的所有课

自己练习： Pygame 在线编辑器