# http://en.wikibooks.org/wiki/Computer_Science_Design_Patterns/Bridge_Pattern#Python # ConcreteImplementor 1/2 class DrawingAPI1(object): def draw_circle(self, x, y, radius): print('API1.circle at {}:{} radius {}'.format(x, y, radius)) # ConcreteImplementor 2/2 class DrawingAPI2(object): def draw_circle(self, x, y, radius): print('API2.circle at {}:{} radius {}'.format(x, y, radius)) # Refined Abstraction class CircleShape(object): def __init__(self, x, y, radius, drawing_api): self._x = x self._y = y self._radius = radius self._drawing_api = drawing_api # low-level i.e. Implementation specific def draw(self): self._drawing_api.draw_circle(self._x, self._y, self._radius) # high-level i.e. Abstraction specific def scale(self, pct): self._radius *= pct def main(): shapes = ( CircleShape(1, 2, 3, DrawingAPI1()), CircleShape(5, 7, 11, DrawingAPI2()) ) for shape in shapes: shape.scale(2.5) shape.draw() if __name__ == '__main__': main()
点击run it 运行之!!!