def setup(self, background):
        "Setup the screen and boids before starting simulation."
        background('black')
        self.schools = []
        self.sources = []
        for body_color, trim_color in self.SCHOOLS:
            new_school = School(body_color, trim_color)
            new_source = vector.Vector2(random.random() * WIDTH,
                                        random.random() * HEIGHT)
            self.schools.append(new_school)
            self.sources.append(new_source)
        self.pointer = 0
Setup the screen and boids before starting simulation.
recipes/Python/578007_processing_DEMO_Boids/recipe-578007.py