I have a function that renders sprites:
self.sheet = pygame.image.load(file).convert_alpha()
But the sprites with transparency still render with black backgrounds. I can't use colorkey because for some reason my sprites always export with random discrepancies in colour where the colour is a few RGB units off the original colour, causing dots to randomly appear around the sprite.
And yes, the sprites I'm using are .png files, not jpg or jpeg.
So my question is, why isn't convert_alpha working, what can I do to make it work, or what else can I do to reach the same goal?
EDIT: here's the spritesheet: