說明：

1.以下所用的Group均為Group類的對象實例

2.Group類是對AbstractGroup類的繼承

sprite.py文檔中描述如下：

class Group(AbstractGroup):
    """container class for many Sprites

    pygame.sprite.Group(*sprites): return Group

    A simple container for Sprite objects. This class can be subclassed to
    create containers with more specific behaviors. The constructor takes any
    number of Sprite arguments to add to the Group. The group supports the
    following standard Python operations:

        in      test if a Sprite is contained
        len     the number of Sprites contained
        bool    test if any Sprites are contained
        iter    iterate through all the Sprites

    The Sprites in the Group are not ordered, so the Sprites are drawn and
    iterated over in no particular order.

    
 
"""
    def __init__(self, *sprites):
        AbstractGroup.__init__(self)
        self.add(*sprites)

方法一：Group.draw(surface)

說明：對精靈組中的每一個精靈依次調用surface.blit()，依次將精靈組中的精靈繪制在surface上

AbstractGroup類中對其的定義：

    def draw(self, surface):
        """draw all sprites onto the surface

        Group.draw(surface): return None

        Draws all of the member sprites onto the given surface.

        
 
"""
        sprites = self.sprites()
        surface_blit = surface.blit
        for spr in sprites:
            self.spritedict[spr] = surface_blit(spr.image, spr.rect)
        self.lostsprites = []

方法二：Group.update()

說明：對精靈組中的每一個精靈依次調用update()方法，並且update()方法需要自己在自己定義的精靈類中去實現

AbstractGroup類中對其的定義：

    def update(self, *args):
        """call the update method of every member sprite

        Group.update(*args): return None

        Calls the update method of every member sprite. All arguments that
        were passed to this method are passed to the Sprite update function.

        """
        for s in self.sprites():
            s.update(*args)

pygame編組（精靈組）Group中的常用方法介紹