pygame: drawing order for sprite group with sprite.RenderPlain

Question

I've got a sprite group which needs to be drawn in a certain order so its sprites overlap as they should.

However even when sorting the group using operator module function (sorted(self.sprites, key=attrgetter('y','x')) the order is wrong.

How can I fix this behaviour?

Answer 1

Straightforwardly, you can't:

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

Use an OrderedUpdates group instead:

This class derives from pygame.sprite.RenderUpdates - Group class that tracks dirty updates. It maintains the order in which the Sprites were added to the Group for rendering. This makes adding and removing Sprites from the Group a little slower than regular Groups.

Alternatively, you can keep different 'layers' of sprites in different groups, keeping the order of groups correct.