Python的多种对象工厂模式方便代码维护扩展

from abc import ABC, abstractmethod
class Animal(ABC):
    @abstractmethod
    def make_sound(self):
        pass
class Dog(Animal):
    def make_sound(self):
        return "Woof!"
class Cat(Animal):
    def make_sound(self):
        return "Meow!"
class AnimalFactory(ABC):
    @abstractmethod
    def create_animal(self):
        pass
class DogFactory(AnimalFactory):
    def create_animal(self):
        return Dog()
class CatFactory(AnimalFactory):
    def create_animal(self):
        return Cat()
dog_factory = DogFactory()
cat_factory = CatFactory()
dog = dog_factory.create_animal()
cat = cat_factory.create_animal()
print(dog.make_sound())  # 输出: Woof!
print(cat.make_sound())  # 输出: Meow!

from abc import ABC, abstractmethod

# 抽象工厂 - 形状工厂
class ShapeFactory(ABC):
    @abstractmethod
    def create_circle(self):
        pass

    @abstractmethod
    def create_square(self):
        pass

# 具体工厂 - 圆形工厂
class CircleFactory(ShapeFactory):
    def create_circle(self):
        return Circle()

    def create_square(self):
        return None

# 具体工厂 - 正方形工厂
class SquareFactory(ShapeFactory):
    def create_circle(self):
        return None

    def create_square(self):
        return Square()

# 抽象产品 - 形状
class Shape(ABC):
    @abstractmethod
    def draw(self):
        pass

# 具体产品 - 圆形
class Circle(Shape):
    def draw(self):
        return "Drawing Circle"

# 具体产品 - 正方形
class Square(Shape):
    def draw(self):
        return "Drawing Square"

# 使用抽象工厂创建对象
def draw_shapes(factory):
    circle = factory.create_circle()
    square = factory.create_square()

    print(circle.draw() if circle else "Circle not supported")
    print(square.draw() if square else "Square not supported")

# 使用不同的工厂创建形状
draw_shapes(CircleFactory())  # 输出: Drawing Circle / Circle not supported
draw_shapes(SquareFactory())  # 输出: Circle not supported / Drawing Square

class Shape:
    def draw(self):
        pass

# 具体产品 - 圆形
class Circle(Shape):
    def draw(self):
        return "Drawing Circle"

# 具体产品 - 正方形
class Square(Shape):
    def draw(self):
        return "Drawing Square"

# 简单工厂
class SimpleShapeFactory:
    def create_shape(self, shape_type):
        if shape_type == "circle":
            return Circle()
        elif shape_type == "square":
            return Square()
        else:
            raise ValueError("Invalid shape type")

# 使用简单工厂创建对象
factory = SimpleShapeFactory()
circle = factory.create_shape("circle")
square = factory.create_shape("square")

print(circle.draw())  # 输出: Drawing Circle
print(square.draw())  # 输出: Drawing Square