# http://en.wikibooks.org/wiki/Computer_Science_Design_Patterns/Bridge_Pattern#Python # ConcreteImplementor 1/2 class DrawingAPI1: def drawCircle(self, x, y, radius): print('API1.circle at {}:{} radius {}'.format(x, y, radius)) # ConcreteImplementor 2/2 class DrawingAPI2: def drawCircle(self, x, y, radius): print('API2.circle at {}:{} radius {}'.format(x, y, radius)) # Refined Abstraction class CircleShape: def __init__(self, x, y, radius, drawingAPI): self.__x = x self.__y = y self.__radius = radius self.__drawingAPI = drawingAPI # low-level i.e. Implementation specific def draw(self): self.__drawingAPI.drawCircle(self.__x, self.__y, self.__radius) # high-level i.e. Abstraction specific def resizeByPercentage(self, pct): self.__radius *= pct def main(): shapes = ( CircleShape(1, 2, 3, DrawingAPI1()), CircleShape(5, 7, 11, DrawingAPI2()) ) for shape in shapes: shape.resizeByPercentage(2.5) shape.draw() if __name__ == "__main__": main()