def wrap_around(self): """Change the position of the bubble to toroidally "wrap around" if it goes off one edge of the map."""

def wrap_around(self): """Change the position of the bubble to toroidally "wrap around" if it goes off one edge of the map.""" if self.pos.x < 0: self.pos.x += 1 if self.pos.y < 0: self.pos.y += 1 if self.pos.x > 1: self.pos.x -= 1 if self.pos.y > 1: self.pos.y -= 1 Why isn't else used? In addition to efficiency it tells the reader that the author expects at most one of x++ or x-- to happen.