bridge.py

# Implementor
class DrawingAPI:
    def drawCircle(x, y, radius):
        pass


# ConcreteImplementor 1/2
class DrawingAPI1(DrawingAPI):
    def drawCircle(self, x, y, radius):
            print "API1.circle at %f:%f radius %f" % (x, y, radius)


# ConcreteImplementor 2/2
class DrawingAPI2(DrawingAPI):
    def drawCircle(self, x, y, radius):
            print "API2.circle at %f:%f radius %f" % (x, y, radius)


# Abstraction
class Shape:
    # Low-level
    def draw(self):
        pass

    # High-level
    def resizeByPercentage(self, pct):
        pass


# Refined Abstraction
class CircleShape(Shape):
    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()