Python UnboundLocalError：局部变量'；事件'；作业前参考[PYGAME]

我目前正在尝试为学校作业创建一个游戏，为我的一个关卡中的某些事件设置计时器，但“UnboundLocalError”不断出现，我不确定如何修复它。我读过其他一些文章，其中可以将变量设置为全局变量，但我在一些地方尝试过，它仍然会给我相同的错误。我们使用的是python 3.4.3

这是我的密码：

import pygame
import random
import sys
import time
import os

#Global Colours and Variables
BLACK = (0, 0, 0)
RED = (255, 0, 0)
GREEN     = (0, 255, 0)
DARKGREEN = (0, 155, 0)
DARKGRAY  = (40, 40, 40)
BLUE = (23, 176, 199)
WHITE = (255, 255, 255)
WIDTH = 640
HEIGHT = 480
TILE_SIZE = 32
NUM_TILES_WIDTH = WIDTH//TILE_SIZE
NUM_TILES_HEIGHT = HEIGHT//TILE_SIZE
COUNT = 10

COOKIEVENT = pygame.USEREVENT
pygame.time.set_timer(COOKIEVENT, 3000)

REVENT = pygame.USEREVENT + 3
pygame.time.set_timer(REVENT, 5000)

PEVENT = pygame.USEREVENT + 2
pygame.time.set_timer(PEVENT ,5000)

# - level 1 -
MAXHEALTH = 3
SCORE = 0
grave = pygame.sprite.Sprite()


#Global Definitions
candies = pygame.sprite.OrderedUpdates()
def add_candy(candies):
    candy = pygame.sprite.Sprite()
    candy.image = pygame.image.load('cookie.png')
    candy.rect = candy.image.get_rect()
    candy.rect.left = random.randint(1, 19)*32
    candy.rect.top = random.randint(1, 13)*32
    candies.add(candy)

for i in range(10):
    add_candy(candies)

#         OPENING SCREEN DEFINITIONS

def showStartScreen():
    screen.fill((DARKGRAY))
    StartFont = pygame.font.SysFont('Browallia New', 20, bold = False, italic = False)
    first_image = StartFont.render("Instructions: Eat all the good cookies!", True, (255, 255, 255))
    second_image = StartFont.render("Raccoon and purple cookies will kill you!", True, (255, 255, 255))
    third_image = StartFont.render("Collect potions to regain HP!", True, (255, 255, 255))
    first_rect = first_image.get_rect(centerx=WIDTH/2, centery=100)
    second_rect = second_image.get_rect(centerx=WIDTH/2, centery=120)
    third_rect = third_image.get_rect(centerx=WIDTH/2, centery=140)
    screen.blit(first_image, first_rect)
    screen.blit(second_image, second_rect)
    screen.blit(third_image, third_rect)

    while True:
        drawPressKeyMsg()

        if checkForKeyPress():
            pygame.event.get()
            return
        pygame.display.update()

def showlevel2StartScreen():
    screen.fill((DARKGRAY))
    StartFont = pygame.font.SysFont('Browallia New', 20, bold = False, italic = False)
    title_image = StartFont.render("Instructions: Eat all the cookies before the timer runs out!", True, (255, 255, 255))
    title_rect = title_image.get_rect(centerx=WIDTH/2, centery=100)
    screen.blit(title_image, title_rect)

    while True:
        drawPressKeyMsg()

        if checkForKeyPress():
            pygame.event.get()
            return
        pygame.display.update()

def drawPressKeyMsg():
    StartFont = pygame.font.SysFont('Browallia New', 20, bold = False, italic = False)
    pressKeyScreen = StartFont.render('Press any key to play.', True, WHITE)
    pressKeyRect = pressKeyScreen.get_rect(centerx=WIDTH/2, centery=160)
    screen.blit(pressKeyScreen, pressKeyRect)

def checkForKeyPress():
    if len(pygame.event.get(pygame.QUIT)) > 0:
        terminate()

    keyUpEvents = pygame.event.get(pygame.KEYUP)
    if len(keyUpEvents) == 0:
        return None
    if keyUpEvents[0] == pygame.K_ESCAPE:
        terminate()
    return keyUpEvents[0].key

def getRandomLocation():
    return {'x': random.randint(0, TILE_SIZE - 1), 'y': random.randint(0, TILE_SIZE - 1)}

def terminate():
    pygame.quit()
    sys.exit()

#         LEVEL 1 DEFINITIONS

pcandies = pygame.sprite.OrderedUpdates()
def add_candie(pcandies):
    candy = pygame.sprite.Sprite()
    candy.image = pygame.image.load('cookie.png')
    candy.rect = candy.image.get_rect()
    pcandy = pygame.sprite.Sprite()
    pcandy.image = pygame.image.load('pcookie.png')
    pcandy.rect = pcandy.image.get_rect()
    pcandy.rect.left = random.randint(1, 19)*32
    pcandy.rect.top = random.randint(1, 13)*32
    candycollides = pygame.sprite.groupcollide(pcandies, candies, False, True)
    while len(candycollides) > 0:
        pcandies.remove(pcandy)
        pcandy.rect.left = random.randint(1, 19)*32
        pcandy.rect.top = random.randint(1, 13)*32
    pcandies.add(pcandy)

for i in range (5):
    add_candie(pcandies)


raccoons = pygame.sprite.GroupSingle()
def add_raccoon(raccoon):
    raccoon = pygame.sprite.Sprite()
    raccoon.image = pygame.image.load('enemy.gif')
    raccoon.rect = raccoon.image.get_rect()
    raccoon.rect.left = random.randint(1, 19)*32
    raccoon.rect.top = random.randint(1, 13)*32
    raccoon.add(raccoons)

potions = pygame.sprite.GroupSingle()
def add_potion(potion):
    potion = pygame.sprite.Sprite()
    potion.image = pygame.image.load('potion.gif')
    potion.rect = potion.image.get_rect()
    potion.rect.left = random.randint(1, 20)*32
    potion.rect.top = random.randint(1, 13)*32
    potion.add(potions)

#Classes

class Wall(pygame.sprite.Sprite):

    def __init__(self, x, y, width, height, color):
        """ Constructor function """

        #Call the parent's constructor
        super().__init__()

        self.image = pygame.screen([width, height])
        self.image.fill(BLUE)

        self.rect = self.image.get_rect()
        self.rect.y = y
        self.rect.x = x

class Room():

    #Each room has a list of walls, and of enemy sprites.
    wall_list = None
    candies = None

    def __init__(self):
        self.wall_list = pygame.sprite.Group()
        self.candies = pygame.sprite.Group

class Player(pygame.sprite.Sprite):



    # Set speed vector
    change_x = 0
    change_y = 0

    def __init__(self, x, y):

        super().__init__()

        #Setting up main character + Adding image/properties to hero!
        player = pygame.sprite.Sprite()
        player.image = pygame.image.load('rabbit.png')
        player_group = pygame.sprite.GroupSingle(hero)
        player.rect = player.image.get_rect()
        player.rect.y = y
        player.rect.x = x

    def changespeed(self, x, y):
        """ Change the speed of the player. Called with a keypress. """
        player.change_x += x
        player.change_y += y


    def move(self, walls):
        """ Find a new position for the player """

        # Move left/right
        player.rect.x += player.change_x

        # Did this update cause us to hit a wall?
        block_hit_list = pygame.sprite.spritecollide(player, walls, False)
        for block in block_hit_list:
            # If we are moving right, set our right side to the left side of
            # the item we hit
            if player.change_x > 0:
                player.rect.right = block.rect.left
            else:
                # Otherwise if we are moving left, do the opposite.
                player.rect.left = block.rect.right

        # Move up/down
        player.rect.y += player.change_y

        # Check and see if we hit anything
        block_hit_list = pygame.sprite.spritecollide(self, walls, False)
        for block in block_hit_list:

            # Reset our position based on the top/bottom of the object.
            if player.change_y > 0:
                player.rect.bottom = block.rect.top
            else:
                player.rect.top = block.rect.bottom

class levelwalls(Room):

    def __init__(self):
        Room.__init__(self)
        #Make the walls. (x_pos, y_pos, width, height)

        # This is a list of walls. Each is in the form [x, y, width, height]

        walls = [[0, 0, 20, 250, WHITE],
                 [0, 350, 20, 250, WHITE],
                 [780, 0, 20, 250, WHITE],
                 [780, 350, 20, 250, WHITE],
                 [20, 0, 760, 20, WHITE],
                 [20, 580, 760, 20, WHITE],
                 [390, 50, 20, 500, BLUE]
                ]

        # Loop through the list. Create the wall, add it to the list
        for item in walls:
            wall = Wall(item[0], item[1], item[2], item[3], item[4])
            self.wall_list.add(wall)

def main():
    pygame.init()
    global FPSCLOCK, screen, my_font, munch_sound, bunny_sound, potion_sound, COOKIEVENT, PEVENT, REVENT 

    FPSCLOCK = pygame.time.Clock()
    munch_sound = pygame.mixer.Sound('crunch.wav')
    bunny_sound = pygame.mixer.Sound('sneeze.wav')
    screen = pygame.display.set_mode((WIDTH,HEIGHT))
    my_font = pygame.font.SysFont('Browallia New', 34, bold = False, italic = False)
    pygame.display.set_caption('GRABBIT')
    #Sounds
    pygame.mixer.music.load('Music2.mp3')
    pygame.mixer.music.play(-1,0.0)
    potion_sound = pygame.mixer.Sound('Correct.wav')

    COOKIEVENT = pygame.USEREVENT
    pygame.time.set_timer(COOKIEVENT, 3000)

    REVENT = pygame.USEREVENT + 3
    pygame.time.set_timer(REVENT, 5000)

    PEVENT = pygame.USEREVENT + 2
    pygame.time.set_timer(PEVENT ,5000)

    showStartScreen()
    while True:
        level1_init()
        showGameOverScreen


def level1_init():
    global COOKIEVENT, PEVENT, REVENT

    finish = False
    win = False
    gameOverMode = False
    move = True
    MAXHEALTH = 3
    SCORE = 0
    count = 10

    COOKIEVENT = pygame.USEREVENT
    pygame.time.set_timer(COOKIEVENT, 3000)

    REVENT = pygame.USEREVENT + 3
    pygame.time.set_timer(REVENT, 5000)

    PEVENT = pygame.USEREVENT + 2
    pygame.time.set_timer(PEVENT ,5000)

    while True:
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                terminate()
            if event.type == pygame.KEYDOWN and event.key == pygame.K_ESCAPE:
                terminate()

        def drawHealthMeter(currentHealth):
                    for i in range(currentHealth): # draw health bars
                        pygame.draw.rect(screen, BLUE,   (15, 5 + (10 * MAXHEALTH) - i * 10, 20, 10))
                    for i in range(MAXHEALTH): # draw the white outlines
                        pygame.draw.rect(screen, WHITE, (15, 5 + (10 * MAXHEALTH) - i * 10, 20, 10), 1)

        if event.type == COOKIEVENT:
            if win == False and gameOverMode == False:
                add_candy(candies)
        if event.type == PEVENT:
            if win == False and gameOverMode == False:
                add_potion(potions)
        if event.type == REVENT:
            if win == False and gameOverMode == False:
                add_raccoon(raccoons)
        if move == True:
            if event.type == pygame.KEYDOWN:
                if event.key == pygame.K_UP:
                    hero.rect.top -= TILE_SIZE
                elif event.key == pygame.K_DOWN:
                    hero.rect.top += TILE_SIZE
                elif event.key == pygame.K_RIGHT:
                    hero.rect.right += TILE_SIZE
                elif event.key == pygame.K_LEFT:
                    hero.rect.right -= TILE_SIZE
                elif event.key == pygame.K_ESCAPE:
                    terminate()

            screen.fill((DARKGRAY))
            grass = pygame.image.load('grass.jpg')
            for x in range(int(WIDTH/grass.get_width()+3)):
                for y in range(int(HEIGHT/grass.get_height()+3)):
                    screen.blit(grass,(x*100,y*100))

            candies.draw(screen)
            pcandies.draw(screen)
            potions.draw(screen)
            hero_group.draw(screen)
            raccoons.draw(screen)
            playerObj = {'health': MAXHEALTH}
            drawHealthMeter(playerObj['health'])


            #Collision with Raccoon
            instantdeath = pygame.sprite.groupcollide(hero_group, raccoons, False, True)
            if len(instantdeath) > 0:
                bunny_sound.play()
                MAXHEALTH = 0

            #Health Potions
            morehealth = pygame.sprite.groupcollide(hero_group, potions, False, True)
            if len(morehealth) > 0:
                potion_sound.play()
                MAXHEALTH = MAXHEALTH + 1

                #Collision with Bad Cookies
            bad = pygame.sprite.groupcollide(hero_group, pcandies, False, True)
            if len(bad) > 0:
                bunny_sound.play()
                MAXHEALTH = MAXHEALTH - 1
            if playerObj['health'] == 0:
                gameOverMode = True
                move = False
                grave.image = pygame.image.load('grave.png')
                grave.rect = grave.image.get_rect(left = hero.rect.left, top = hero.rect.top)
                screen.blit(grave.image, grave.rect)

            #Collision with Good Cookies
            collides = pygame.sprite.groupcollide(hero_group, candies, False, True)
            if len(collides) > 0:
                munch_sound.play()
                SCORE += 1
            if len(candies) == 0:
                win = True

            scoretext = my_font.render("Score = "+str(SCORE), 1, (255, 255, 255))
            screen.blit(scoretext, (520, 5))

            #If you collide with Racoon
            if gameOverMode == True:
                font = pygame.font.SysFont('Browallia New', 36, bold = False, italic = False)
                text_image = font.render("You Lose. Game Over!", True, (255, 255, 255))
                text_rect = text_image.get_rect(centerx=WIDTH/2, centery=100)
                screen.blit(text_image, text_rect)

            if win:
                move = False
                CEVENT = pygame.USEREVENT + 5
                pygame.time.set_timer(CEVENT, 1000)
                if count > 0:
                    if event.type == CEVENT:
                        count -= 1
                text_image = my_font.render('You won! Next level will begin in ' + str(count) + ' seconds', True, (255, 255, 255))
                text_rect = text_image.get_rect(centerx=WIDTH/2, centery=100)
                screen.blit(text_image, text_rect)
                score_text_image = my_font.render("You achieved a score of " + str(SCORE), True, (255, 255, 255))
                score_text_rect = score_text_image.get_rect(centerx = WIDTH/2, centery = 150)
                screen.blit(score_text_image, score_text_rect)
                if count == 0:
                    showlevel2StartScreen()
                    win = False
                    level2_init()


            pygame.display.update()



main()
pygame.quit()

错误如下所示：

Traceback (most recent call last):
  File "F:\Year 10\IST\Programming\Pygame\Final Game\Final Game - Grabbit.py", line 426, in <module>
    main()
  File "F:\Year 10\IST\Programming\Pygame\Final Game\Final Game - Grabbit.py", line 284, in main
    level1_init()
  File "F:\Year 10\IST\Programming\Pygame\Final Game\Final Game - Grabbit.py", line 324, in level1_init
    if event.type == COOKIEVENT:
UnboundLocalError: local variable 'event' referenced before assignment

回溯（最近一次呼叫最后一次）：
文件“F:\Year 10\IST\Programming\Pygame\Final Game\Final Game-Grabbit.py”，第426行，在
main（）
文件“F:\Year 10\IST\Programming\Pygame\Final Game\Final Game-Grabbit.py”，第284行，主文件
级别1_init（）
文件“F:\Year 10\IST\Programming\Pygame\Final Game\Final Game-Grabbit.py”，第324行，在level1\u init中
如果event.type==CookieEvent：
UnboundLocalError:赋值前引用的局部变量“event”

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有人能建议我如何解决这个问题吗？如果您能为我的代码提供一些改进建议，我将不胜感激。我是python的初学者，这是我使用这种编码语言进行的第一个项目。谢谢。

行中未初始化

事件

变量

if event.type == COOKIEVENT:

您可能需要缩进代码的这一部分，以便它进入循环中

for event in pygame.event.get():
   ....
   if event.type == COOKIEVENT:`

---

非常感谢。我正在阅读我的代码，我意识到就在我发布这个之后！