在 pygame 中发出运行函数

问题描述

import pygame
import random
import time

pygame.init()
backX = 1000
backY = 600
screen = pygame.display.set_mode((backX,backY))

score = 0
white = (255,255,255)
green = (0,0)
blue = (0,128)
timespent = 0
pygame.display.set_caption('Monkey Simulator')  # game name
pygame.font.init()  # you have to call this at the start,# if you want to use this module.
myfont = pygame.font.SysFont('Comic Sans MS',30)
textsurface = myfont.render('score: ' + str(score),False,(255,255))
pygame.mixer.init()
# music
sound = pygame.mixer.sound('background1.mp3')
collection = pygame.mixer.sound('collection.mp3')
gameover1 = pygame.mixer.sound('gameover.mp3')
sound.play(-1)
# score indicator
text = myfont.render('score: ' + str(score),True,white,blue)

textRect = text.get_rect()  # getting the rectangle for the text object

textRect.center = (400 // 2,400 // 2)
pre_background = pygame.image.load('background.jpeg')

background = pygame.transform.scale(pre_background,(backX,backY))
clock = pygame.time.Clock()
FPS = 60
vel = 6.5
BLACK = (0,0)
monkeyimg = pygame.image.load('monkey.png')
playerX = 410
playerY = 435
bananaveLocity = 4
monkey = pygame.transform.scale(monkeyimg,(100,120))
prebanana = pygame.image.load('banana.png')
bananaXList = []
def change():
    if score>=5:
        monkey = pygame.transform.scale(pre_shark,100))
        banana = pygame.transform.scale(pre_meat,(50,50))
        background = pygame.transform.scale(underwater,backY))
for i in range(50):
    value = random.randint(10,980)
    bananaXList.append(value)
valuenumber = random.randint(1,30)
bananaX = bananaXList[valuenumber - 1]
bananaY = 0
banana = pygame.transform.scale(prebanana,50))
underwater = pygame.image.load('underwater.jpg')
pre_shark = pygame.image.load('shark.png')
pre_meat = pygame.image.load('meat.png')
banana_rect = banana.get_rect(topleft=(bananaX,bananaY))
monkey_rect = monkey.get_rect(topleft=(playerX,playerY))
run = True
black = (0,0)

    # start screen
screen.blit(background,(0,0))
myfont = pygame.font.SysFont("Britannic Bold",50)
end_it = False

while not end_it:
    myfont1 = pygame.font.SysFont("Britannic Bold",35)

    nlabel = myfont.render("Monkey Simulator",1,255))
    info = myfont1.render("Use your right and left arrow keys to move the character.",255))
    info2 = myfont1.render("Try to catch as many bananas as you can while the game speeds up!",255))

    for event in pygame.event.get():
        if event.type == pygame.MOUSEBUTTONDOWN:
            end_it = True
    screen.blit(nlabel,(400,150))
    screen.blit(info,300))
    screen.blit(info2,350))

    pygame.display.flip()

while run:
    clock.tick(FPS)
    screen.fill(BLACK)
    screen.blit(background,0))
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            run = False
    keys = pygame.key.get_pressed()
    # banana animation
    bananaY = bananaY + bananaveLocity
    timespent = int(pygame.time.get_ticks() / 1000)
    bananaveLocity = 4 + (timespent * 0.055)
    vel = 6.5 + (timespent * 0.07)
    # end game sequence
    change()
    if bananaY > 510:
        bananaX = -50
        bananaY = -50
        banana

        veLocity = 0
        gameover = pygame.image.load("gameover.jpg")
        background = pygame.transform.scale(gameover,backY))
        pygame.mixer.sound.stop(sound)
        gameover1.play()

    # collecting coins sequence
    if banana_rect.colliderect(monkey_rect):
        collection.play()
        valuenumber = random.randint(1,30)
        bananaX = bananaXList[valuenumber - 1]
        bananaY = -25
        score += 1

    # moving character
    if keys[pygame.K_LEFT] and playerX > 0:
        playerX = playerX - vel
    if keys[pygame.K_RIGHT] and playerX < 930:
        playerX = playerX + vel
    # adding the sprites to the screen
    screen.blit(monkey,(playerX,playerY))
    screen.blit(banana,(bananaX,bananaY))
    banana_rect = banana.get_rect(topleft=(bananaX,bananaY))
    monkey_rect = monkey.get_rect(topleft=(playerX,playerY))
    pygame.draw.rect(screen,(150,75,0),pygame.Rect(0,534,1000,20))
    screen.blit(textsurface,(30,0))
    textsurface = myfont.render('score: ' + str(score),255))

    pygame.display.update()

现在我正在制作一款收集游戏。一旦你达到某个分数，我想使用一个函数来替换所有图像。但是，无论您获得多高的分数，它都不起作用。我不明白这个问题，因为我通过放置打印语句测试了函数和 if 语句。

解决方法

如果要更改函数内全局命名空间中的变量，则必须使用 global statement：

def change():
    global monkey,banana,background 
  
    if score>=5:
        monkey = pygame.transform.scale(pre_shark,(100,100))
        banana = pygame.transform.scale(pre_meat,(50,50))
        background = pygame.transform.scale(underwater,(backX,backY))

如果不使用 global 语句，则将值分配给函数作用域内的局部变量。

另一种选择是从函数返回新值：

def change():
    if score>=5:
        return ( 
            pygame.transform.scale(pre_shark,100)),pygame.transform.scale(pre_meat,50)),pygame.transform.scale(underwater,backY)) )
    return monkey,background

while True:
    # [...]

    monkey,background = change()

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