Pygame无效的语法我无法弄清楚

Question

我一直在学习"McGugan - 使用Python和Pygame开始游戏开发(Apress,2007)"的教程,并且在第五章涉及对象移动的代码中,我一直在代码中使用" - "上获得无效的语法警报.它不是最新的,但我认为由于其简单性和必要性,任何更新都不会更改减法.

这是我的代码:

background_image_filename = 'sushiplate.jpg'
sprite_image_filename = 'fugu.png'
import pygame
from pygame.locals import *
from sys import exit
from gameobjects.vector2 import Vector2
pygame.init()
screen = pygame.display.set_mode((640, 480), 0, 32)
background = pygame.image.load(background_image_filename).convert()
sprite = pygame.image.load(sprite_image_filename).convert_alpha()
clock = pygame.time.Clock()
position = Vector2(100.0, 100.0)
speed = 250.
heading = Vector2()
while True:
    for event in pygame.event.get():
        if event.type == QUIT:
            exit()
    if event.type == MOUSEBUTTONDOWN:
        destination = Vector2(*event.pos) – Vector2(*sprite.get_size())/2.
        heading = Vector2.from_points(position, destination)
        heading.normalize()
    screen.blit(background, (0,0))
    screen.blit(sprite, position)
    time_passed = clock.tick()
    time_passed_seconds = time_passed / 1000.0
    distance_moved = time_passed_seconds * speed
    position += heading * distance_moved
    pygame.display.update()

我做错了什么还是只是过时了？

非常需要任何帮助.

Answer 1

在这一行:

destination = Vector2(*event.pos) – Vector2(*sprite.get_size())/2.

你以某种方式键入了字符" –"(EN DASH)而不是" -"(HYPHEN-MINUS).使用" -"(HYPHEN-MINUS)代替,如下所示:

destination = Vector2(*event.pos) - Vector2(*sprite.get_size())/2.