结构型模式 - 外观模式

提供一个供客户端可以访问系统的接口，隐藏系统的复杂性

使用场景

1. 客户端不需要知道服务端复杂的调用关系，只需要调用提供的接口
2. 接待人员

Demo

"""
外观模式
"""
class Shape:
    def draw(self):
        raise NotImplementedError
class Circle(Shape):
    def draw(self):
        print("this is circle")
class Rectangle(Shape):
    def draw(self):
        print("this is rectangle")
class Square(Shape):
    def draw(self):
        print("this is square")
class ShapeMaker:
    def __init__(self):
        self.circle = Circle()
        self.rectangle = Rectangle()
        self.square = Square()
    def draw_circle(self):
        self.circle.draw()
    def draw_rectangle(self):
        self.rectangle.draw()
    def draw_square(self):
        self.square.draw()
if __name__ == '__main__':
    s = ShapeMaker()
    s.draw_circle()
    s.draw_square()
    s.draw_rectangle()