Python编程从入门到实践---pygame精灵组

初学Python，跟着书上的外星人项目，写了一下，碰到一个这样的问题：

AttributeError: 'Alien' object has no attribute 'add_internal'

找到的原因是，精灵组里面只能添加精灵，不能添加其他的非精灵的类，这也是我在这里犯的错。将需要添加到精灵组的类，需要继承Sprite类，犯错代码块如下：

正确的是：

 

既然碰到了精灵组，那就放些相关的知识吧。

pygame.sprite的官网api

https://www.pygame.org/docs/ref/sprite.html?highlight=sprite#module-pygame.sprite

常用的sprite方法

 

 

sprites()

list of the Sprites this Group contains

sprites() -> sprite_list

Return a list of all the Sprites this group contains. You can also get an iterator from the group, but you cannot iterator over a Group while modifying it.

copy()

duplicate the Group

copy() -> Group

Creates a new Group with all the same Sprites as the original. If you have subclassed Group, the new object will have the same (sub-)class as the original. This only works if the derived class's constructor takes the same arguments as the Group class's.

add()

add Sprites to this Group

add(*sprites) -> None

Add any number of Sprites to this Group. This will only add Sprites that are not already members of the Group.

Each sprite argument can also be a iterator containing Sprites.

remove()

remove Sprites from the Group

remove(*sprites) -> None

Remove any number of Sprites from the Group. This will only remove Sprites that are already members of the Group.

Each sprite argument can also be a iterator containing Sprites.

has()

test if a Group contains Sprites

has(*sprites) -> None

Return True if the Group contains all of the given sprites. This is similar to using the "in" operator on the Group ("if sprite in group: ..."), which tests if a single Sprite belongs to a Group.

Each sprite argument can also be a iterator containing Sprites.

update()

call the update method on contained Sprites

update(*args) -> None

Calls the update() method on all Sprites in the Group. The base Sprite class has an update method that takes any number of arguments and does nothing. The arguments passed to Group.update() will be passed to each Sprite.

There is no way to get the return value from the Sprite.update() methods.

draw()

blit the Sprite images

draw(Surface) -> None

Draws the contained Sprites to the Surface argument. This uses the Sprite.image attribute for the source surface, and Sprite.rect for the position.

The Group does not keep sprites in any order, so the draw order is arbitrary.

clear()

draw a background over the Sprites

clear(Surface_dest, background) -> None

Erases the Sprites used in the last Group.draw() call. The destination Surface is cleared by filling the drawn Sprite positions with the background.

The background is usually a Surface image the same dimensions as the destination Surface. However, it can also be a callback function that takes two arguments; the destination Surface and an area to clear. The background callback function will be called several times each clear.

Here is an example callback that will clear the Sprites with solid red:

def clear_callback(surf, rect):
    color = 255, 0, 0
    surf.fill(color, rect)

empty()

remove all Sprites

empty() -> None

Removes all Sprites from this Group.