class 没有被 del 销毁的实例

Question

我正在尝试删除一个对象（在本例中为 Fruit class 的实例），当它与我的蛇头相交时。问题是当它检测到水果对象时，del 似乎没有做任何事情。不知道是我没有正确实现delete函数，还是我把对象喂给函数的方式有关。

这是处理游戏功能的 main.py 脚本的一部分：

    # Main loop
    while running:
        # event handling, gets all event from the event queue
        for event in pygame.event.get():
            # only do something if the event is of type QUIT
            if event.type == pygame.QUIT:
                # change the value to False, to exit the main loop
                running = False

        # Modify game fruit properties
        if fruit_tick < 50:
            fruit_tick += 1
        else:
            game.spawn_fruit()
            fruit_tick = 0

        # Modify game player properties
        if not game.player_python:
            game.spawn_player()
        else:
            game.player_python.move()
            game.player_python.detect_object(game.get_objects())

        # Modify display properties
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
        game.draw_shapes()
        pygame.display.flip()

这是当头部与 Fruit 对象位于同一位置时正在执行的函数：

    # Detect object
    def detect_object(self, objects):
        for obj in objects:
            if obj.pivot == self.location:
                if isinstance(obj, Fruit):
                    self.grow(obj.get_growth())
                    del obj

如果我在if isinstance(obj, Fruit):下添加一个print()语句，它执行没有问题。问题是 del obj 什么都不做。

Answer 1

不要在循环遍历列表时删除迭代器变量或列表中的项目，因为这是一种不好的做法，无论如何，请尝试另一种方法。也许可以这样删除一些对象：

# Detect object
def detect_object(self, objects):
    del_indices = []

    for i in len(objects):
        obj = objects[i]

        if obj.pivot == self.location:
            if isinstance(obj, Fruit):
                self.grow(obj.get_growth())
                # del obj
                del_indices.append(i)

    # Remove some objects
    new_objects = []

    for i in len(objects):
        if not i in del_indices:
            new_objects.append(objects[i])

    objects = new_objects
    # return objects

class 没有被 del 销毁的实例

Instance of a class not being destroyed with del

python

pygame

object

instance

del