82 lines
1.7 KiB
Python
82 lines
1.7 KiB
Python
"""
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实例：
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汤宝宝坚信搭积木是人类的未来，因此开办了一家积木厂。
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"""
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from abc import ABC, abstractmethod
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# 抽象Node接口 Shape
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class Shape(ABC):
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@abstractmethod
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def accept(self, visitor: "Visitor"):
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pass
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@abstractmethod
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def claim_shape(self):
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pass
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class Circle(Shape):
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def accept(self, visitor):
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visitor.visit_circle(self)
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def claim_shape(self):
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print("I am a Circle")
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class Square(Shape):
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def accept(self, visitor):
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visitor.visit_square(self)
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def claim_shape(self):
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print("I am a Square")
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class Triangle(Shape):
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def accept(self, visitor):
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visitor.visit_triangle(self)
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def claim_shape(self):
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print("I am a Triangle")
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# 抽象Visitor接口
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class Visitor(ABC):
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@abstractmethod
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def visit_circle(self, circle: Circle):
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pass
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@abstractmethod
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def visit_square(self, square: Square):
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pass
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@abstractmethod
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def visit_triangle(self, triangle: Triangle):
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pass
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# 具体Visitor实现
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class ShapeVisitor(Visitor):
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def visit_circle(self, circle: Circle):
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print("Visiting Circle:", end=" ")
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circle.claim_shape()
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def visit_square(self, square: Square):
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print("Visiting Square:", end=" ")
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square.claim_shape()
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def visit_triangle(self, triangle: Triangle):
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print("Visiting Triangle:", end=" ")
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triangle.claim_shape()
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if __name__ == "__main__":
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print("========== 访问者模式 ==========")
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shapes = [Circle(), Square(), Triangle()]
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visitor = ShapeVisitor()
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for shape in shapes:
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shape.accept(visitor)
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print("\n======== 访问者模式结束 ========")
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