# 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！！！