\u8bbe\u8ba1\u6a21\u5f0f\u662f\u8f6f\u4ef6\u5de5\u7a0b\u4e2d\u7684\u6700\u4f73\u5b9e\u8df5\uff0cPython \u4f5c\u4e3a\u4e00\u95e8\u7075\u6d3b\u7684\u8bed\u8a00\uff0c\u4e3a\u5404\u79cd\u8bbe\u8ba1\u6a21\u5f0f\u7684\u5b9e\u73b0\u63d0\u4f9b\u4e86\u4f18\u96c5\u7684\u8bed\u6cd5\u652f\u6301\u3002\u672c\u6587\u5c06\u901a\u8fc7\u5b9e\u9645\u573a\u666f\u6df1\u5165\u8bb2\u89e3 23 \u79cd\u8bbe\u8ba1\u6a21\u5f0f\u5728 Python \u4e2d\u7684\u843d\u5730\u5e94\u7528\uff0c\u5e2e\u52a9\u8bfb\u8005\u638c\u63e1\u8bbe\u8ba1\u6a21\u5f0f\u7684\u5b9e\u9645\u8fd0\u7528\u3002<\/p>\n
\u521b\u5efa\u578b\u6a21\u5f0f\u5173\u6ce8\u5bf9\u8c61\u7684\u521b\u5efa\u8fc7\u7a0b\uff0c\u63d0\u4f9b\u4e86\u7075\u6d3b\u7684\u5bf9\u8c61\u521b\u5efa\u673a\u5236\u3002<\/p>\n
\u5355\u4f8b\u6a21\u5f0f\u786e\u4fdd\u4e00\u4e2a\u7c7b\u53ea\u6709\u4e00\u4e2a\u5b9e\u4f8b\uff0c\u5e76\u63d0\u4f9b\u5168\u5c40\u8bbf\u95ee\u70b9\u3002<\/p>\n
class Singleton:\n _instance = None\n \n def __new__(cls):\n if cls._instance is None:\n cls._instance = super().__new__(cls)\n cls._instance.initialized = False\n return cls._instance\n \n def __init__(self):\n if not self.initialized:\n self.value = 0\n self.initialized = True\n\ndef singleton_demo():\n print("\u5355\u4f8b\u6a21\u5f0f\u6f14\u793a:")\n \n s1 = Singleton()\n s2 = Singleton()\n \n print(f"s1 is s2: {s1 is s2}")\n print(f"s1.value: {s1.value}")\n \n s1.value = 100\n print(f"s2.value: {s2.value}")\n\nsingleton_demo()<\/code><\/pre>\n\u5de5\u5382\u65b9\u6cd5\u6a21\u5f0f<\/h4>\n
\u5de5\u5382\u65b9\u6cd5\u6a21\u5f0f\u5b9a\u4e49\u521b\u5efa\u5bf9\u8c61\u7684\u63a5\u53e3\uff0c\u8ba9\u5b50\u7c7b\u51b3\u5b9a\u5b9e\u4f8b\u5316\u54ea\u4e2a\u7c7b\u3002<\/p>\n
from abc import ABC, abstractmethod\n\nclass Animal(ABC):\n @abstractmethod\n def make_sound(self):\n pass\n\nclass Dog(Animal):\n def make_sound(self):\n return "\u6c6a\u6c6a"\n\nclass Cat(Animal):\n def make_sound(self):\n return "\u55b5\u55b5"\n\nclass AnimalFactory:\n @staticmethod\n def create_animal(animal_type):\n if animal_type == "dog":\n return Dog()\n elif animal_type == "cat":\n return Cat()\n else:\n raise ValueError("\u672a\u77e5\u7684\u52a8\u7269\u7c7b\u578b")\n\ndef factory_method_demo():\n print("\u5de5\u5382\u65b9\u6cd5\u6a21\u5f0f\u6f14\u793a:")\n \n dog = AnimalFactory.create_animal("dog")\n cat = AnimalFactory.create_animal("cat")\n \n print(f"\u72d7\u53eb\u58f0: {dog.make_sound()}")\n print(f"\u732b\u53eb\u58f0: {cat.make_sound()}")\n\nfactory_method_demo()<\/code><\/pre>\n\u62bd\u8c61\u5de5\u5382\u6a21\u5f0f<\/h4>\n
\u62bd\u8c61\u5de5\u5382\u6a21\u5f0f\u63d0\u4f9b\u521b\u5efa\u76f8\u5173\u6216\u4f9d\u8d56\u5bf9\u8c61\u7684\u63a5\u53e3\uff0c\u65e0\u9700\u6307\u5b9a\u5177\u4f53\u7c7b\u3002<\/p>\n
from abc import ABC, abstractmethod\n\nclass Button(ABC):\n @abstractmethod\n def render(self):\n pass\n\nclass Checkbox(ABC):\n @abstractmethod\n def render(self):\n pass\n\nclass WindowsButton(Button):\n def render(self):\n return "Windows \u6309\u94ae"\n\nclass WindowsCheckbox(Checkbox):\n def render(self):\n return "Windows \u590d\u9009\u6846"\n\nclass MacButton(Button):\n def render(self):\n return "Mac \u6309\u94ae"\n\nclass MacCheckbox(Checkbox):\n def render(self):\n return "Mac \u590d\u9009\u6846"\n\nclass GUIFactory(ABC):\n @abstractmethod\n def create_button(self):\n pass\n \n @abstractmethod\n def create_checkbox(self):\n pass\n\nclass WindowsFactory(GUIFactory):\n def create_button(self):\n return WindowsButton()\n \n def create_checkbox(self):\n return WindowsCheckbox()\n\nclass MacFactory(GUIFactory):\n def create_button(self):\n return MacButton()\n \n def create_checkbox(self):\n return MacCheckbox()\n\ndef abstract_factory_demo():\n print("\u62bd\u8c61\u5de5\u5382\u6a21\u5f0f\u6f14\u793a:")\n \n windows_factory = WindowsFactory()\n mac_factory = MacFactory()\n \n print(f"Windows: {windows_factory.create_button().render()}, {windows_factory.create_checkbox().render()}")\n print(f"Mac: {mac_factory.create_button().render()}, {mac_factory.create_checkbox().render()}")\n\nabstract_factory_demo()<\/code><\/pre>\n\u5efa\u9020\u8005\u6a21\u5f0f<\/h4>\n
\u5efa\u9020\u8005\u6a21\u5f0f\u5c06\u590d\u6742\u5bf9\u8c61\u7684\u6784\u5efa\u4e0e\u8868\u793a\u5206\u79bb\uff0c\u4f7f\u5f97\u540c\u6837\u7684\u6784\u5efa\u8fc7\u7a0b\u53ef\u4ee5\u521b\u5efa\u4e0d\u540c\u7684\u8868\u793a\u3002<\/p>\n
class Computer:\n def __init__(self):\n self.cpu = None\n self.memory = None\n self.storage = None\n \n def __str__(self):\n return f"CPU: {self.cpu}, \u5185\u5b58: {self.memory}, \u5b58\u50a8: {self.storage}"\n\nclass ComputerBuilder:\n def __init__(self):\n self.computer = Computer()\n \n def set_cpu(self, cpu):\n self.computer.cpu = cpu\n return self\n \n def set_memory(self, memory):\n self.computer.memory = memory\n return self\n \n def set_storage(self, storage):\n self.computer.storage = storage\n return self\n \n def build(self):\n return self.computer\n\ndef builder_demo():\n print("\u5efa\u9020\u8005\u6a21\u5f0f\u6f14\u793a:")\n \n computer = (ComputerBuilder()\n .set_cpu("Intel i7")\n .set_memory("16GB")\n .set_storage("512GB SSD")\n .build())\n \n print(f"\u914d\u7f6e\u7684\u7535\u8111: {computer}")\n\nbuilder_demo()<\/code><\/pre>\n\u539f\u578b\u6a21\u5f0f<\/h4>\n
\u539f\u578b\u6a21\u5f0f\u901a\u8fc7\u590d\u5236\u73b0\u6709\u5bf9\u8c61\u6765\u521b\u5efa\u65b0\u5bf9\u8c61\uff0c\u63d0\u9ad8\u521b\u5efa\u6548\u7387\u3002<\/p>\n
import copy\n\nclass Prototype:\n def __init__(self, value):\n self.value = value\n \n def clone(self):\n return copy.deepcopy(self)\n\ndef prototype_demo():\n print("\u539f\u578b\u6a21\u5f0f\u6f14\u793a:")\n \n original = Prototype("\u539f\u59cb\u5bf9\u8c61")\n cloned = original.clone()\n \n print(f"\u539f\u59cb\u5bf9\u8c61: {original.value}")\n print(f"\u514b\u9686\u5bf9\u8c61: {cloned.value}")\n print(f"\u662f\u5426\u76f8\u540c: {original is cloned}")\n\nprototype_demo()<\/code><\/pre>\n\u7ed3\u6784\u578b\u6a21\u5f0f<\/h3>\n
\u7ed3\u6784\u578b\u6a21\u5f0f\u5173\u6ce8\u7c7b\u548c\u5bf9\u8c61\u7684\u7ec4\u5408\uff0c\u5f62\u6210\u66f4\u5927\u7684\u7ed3\u6784\u3002<\/p>\n
\u9002\u914d\u5668\u6a21\u5f0f<\/h4>\n
\u9002\u914d\u5668\u6a21\u5f0f\u5c06\u4e00\u4e2a\u7c7b\u7684\u63a5\u53e3\u8f6c\u6362\u6210\u5ba2\u6237\u5e0c\u671b\u7684\u53e6\u4e00\u4e2a\u63a5\u53e3\u3002<\/p>\n
class Target:\n def request(self):\n return "\u76ee\u6807\u63a5\u53e3"\n\nclass Adaptee:\n def specific_request(self):\n return "\u7279\u5b9a\u63a5\u53e3"\n\nclass Adapter(Target):\n def __init__(self, adaptee):\n self.adaptee = adaptee\n \n def request(self):\n return self.adaptee.specific_request()\n\ndef adapter_demo():\n print("\u9002\u914d\u5668\u6a21\u5f0f\u6f14\u793a:")\n \n adaptee = Adaptee()\n adapter = Adapter(adaptee)\n \n print(f"\u9002\u914d\u5668\u8bf7\u6c42: {adapter.request()}")\n\nadapter_demo()<\/code><\/pre>\n\u6865\u63a5\u6a21\u5f0f<\/h4>\n
\u6865\u63a5\u6a21\u5f0f\u5c06\u62bd\u8c61\u4e0e\u5b9e\u73b0\u5206\u79bb\uff0c\u4f7f\u5b83\u4eec\u53ef\u4ee5\u72ec\u7acb\u53d8\u5316\u3002<\/p>\n
class DrawingAPI:\n def draw_circle(self, x, y, radius):\n pass\n\nclass DrawingAPI1(DrawingAPI):\n def draw_circle(self, x, y, radius):\n return f"API1 \u7ed8\u5236\u5706\u5f62: ({x}, {y}), \u534a\u5f84: {radius}"\n\nclass DrawingAPI2(DrawingAPI):\n def draw_circle(self, x, y, radius):\n return f"API2 \u7ed8\u5236\u5706\u5f62: ({x}, {y}), \u534a\u5f84: {radius}"\n\nclass Shape:\n def __init__(self, drawing_api):\n self.drawing_api = drawing_api\n \n def draw(self):\n pass\n\nclass Circle(Shape):\n def __init__(self, x, y, radius, drawing_api):\n super().__init__(drawing_api)\n self.x = x\n self.y = y\n self.radius = radius\n \n def draw(self):\n return self.drawing_api.draw_circle(self.x, self.y, self.radius)\n\ndef bridge_demo():\n print("\u6865\u63a5\u6a21\u5f0f\u6f14\u793a:")\n \n circle1 = Circle(1, 2, 3, DrawingAPI1())\n circle2 = Circle(4, 5, 6, DrawingAPI2())\n \n print(circle1.draw())\n print(circle2.draw())\n\nbridge_demo()<\/code><\/pre>\n\u7ec4\u5408\u6a21\u5f0f<\/h4>\n
\u7ec4\u5408\u6a21\u5f0f\u5c06\u5bf9\u8c61\u7ec4\u5408\u6210\u6811\u5f62\u7ed3\u6784\u4ee5\u8868\u793a”\u90e8\u5206-\u6574\u4f53”\u7684\u5c42\u6b21\u7ed3\u6784\u3002<\/p>\n
class Component:\n def operation(self):\n pass\n \n def add(self, component):\n pass\n \n def remove(self, component):\n pass\n\nclass Leaf(Component):\n def operation(self):\n return "\u53f6\u5b50\u8282\u70b9"\n\nclass Composite(Component):\n def __init__(self):\n self.children = []\n \n def add(self, component):\n self.children.append(component)\n \n def remove(self, component):\n self.children.remove(component)\n \n def operation(self):\n results = [child.operation() for child in self.children]\n return f"\u7ec4\u5408\u8282\u70b9: {', '.join(results)}"\n\ndef composite_demo():\n print("\u7ec4\u5408\u6a21\u5f0f\u6f14\u793a:")\n \n leaf1 = Leaf()\n leaf2 = Leaf()\n composite = Composite()\n \n composite.add(leaf1)\n composite.add(leaf2)\n \n print(composite.operation())\n\ncomposite_demo()<\/code><\/pre>\n\u88c5\u9970\u5668\u6a21\u5f0f<\/h4>\n
\u88c5\u9970\u5668\u6a21\u5f0f\u52a8\u6001\u5730\u7ed9\u5bf9\u8c61\u6dfb\u52a0\u989d\u5916\u7684\u804c\u8d23\u3002<\/p>\n
class Component:\n def operation(self):\n return "\u57fa\u672c\u64cd\u4f5c"\n\nclass Decorator(Component):\n def __init__(self, component):\n self.component = component\n \n def operation(self):\n return self.component.operation()\n\nclass ConcreteDecorator(Decorator):\n def operation(self):\n return f"\u88c5\u9970 {super().operation()}"\n\ndef decorator_demo():\n print("\u88c5\u9970\u5668\u6a21\u5f0f\u6f14\u793a:")\n \n component = Component()\n decorated = ConcreteDecorator(component)\n \n print(decorated.operation())\n\ndecorator_demo()<\/code><\/pre>\n\u5916\u89c2\u6a21\u5f0f<\/h4>\n
\u5916\u89c2\u6a21\u5f0f\u4e3a\u5b50\u7cfb\u7edf\u4e2d\u7684\u4e00\u7ec4\u63a5\u53e3\u63d0\u4f9b\u4e00\u4e2a\u4e00\u81f4\u7684\u754c\u9762\u3002<\/p>\n
class SubsystemA:\n def operation_a(self):\n return "\u5b50\u7cfb\u7edf A \u64cd\u4f5c"\n\nclass SubsystemB:\n def operation_b(self):\n return "\u5b50\u7cfb\u7edf B \u64cd\u4f5c"\n\nclass Facade:\n def __init__(self):\n self.subsystem_a = SubsystemA()\n self.subsystem_b = SubsystemB()\n \n def operation(self):\n return f"{self.subsystem_a.operation_a()}, {self.subsystem_b.operation_b()}"\n\ndef facade_demo():\n print("\u5916\u89c2\u6a21\u5f0f\u6f14\u793a:")\n \n facade = Facade()\n print(facade.operation())\n\nfacade_demo()<\/code><\/pre>\n\u4eab\u5143\u6a21\u5f0f<\/h4>\n
\u4eab\u5143\u6a21\u5f0f\u8fd0\u7528\u5171\u4eab\u6280\u672f\u6709\u6548\u5730\u652f\u6301\u5927\u91cf\u7ec6\u7c92\u5ea6\u7684\u5bf9\u8c61\u3002<\/p>\n
class Flyweight:\n def __init__(self, intrinsic_state):\n self.intrinsic_state = intrinsic_state\n \n def operation(self, extrinsic_state):\n return f"\u5185\u8574\u72b6\u6001: {self.intrinsic_state}, \u5916\u8574\u72b6\u6001: {extrinsic_state}"\n\nclass FlyweightFactory:\n def __init__(self):\n self.flyweights = {}\n \n def get_flyweight(self, key):\n if key not in self.flyweights:\n self.flyweights[key] = Flyweight(key)\n return self.flyweights[key]\n\ndef flyweight_demo():\n print("\u4eab\u5143\u6a21\u5f0f\u6f14\u793a:")\n \n factory = FlyweightFactory()\n \n flyweight1 = factory.get_flyweight("\u5171\u4eab\u5bf9\u8c61")\n flyweight2 = factory.get_flyweight("\u5171\u4eab\u5bf9\u8c61")\n \n print(f"\u662f\u5426\u76f8\u540c: {flyweight1 is flyweight2}")\n print(flyweight1.operation("\u5916\u8574\u72b6\u6001 1"))\n print(flyweight2.operation("\u5916\u8574\u72b6\u6001 2"))\n\nflyweight_demo()<\/code><\/pre>\n\u4ee3\u7406\u6a21\u5f0f<\/h4>\n
\u4ee3\u7406\u6a21\u5f0f\u4e3a\u5176\u4ed6\u5bf9\u8c61\u63d0\u4f9b\u4e00\u79cd\u4ee3\u7406\u4ee5\u63a7\u5236\u5bf9\u8fd9\u4e2a\u5bf9\u8c61\u7684\u8bbf\u95ee\u3002<\/p>\n
class Subject:\n def request(self):\n pass\n\nclass RealSubject(Subject):\n def request(self):\n return "\u771f\u5b9e\u8bf7\u6c42"\n\nclass Proxy(Subject):\n def __init__(self):\n self.real_subject = None\n \n def request(self):\n if self.real_subject is None:\n self.real_subject = RealSubject()\n return self.real_subject.request()\n\ndef proxy_demo():\n print("\u4ee3\u7406\u6a21\u5f0f\u6f14\u793a:")\n \n proxy = Proxy()\n print(proxy.request())\n\nproxy_demo()<\/code><\/pre>\n\u884c\u4e3a\u578b\u6a21\u5f0f<\/h3>\n
\u884c\u4e3a\u578b\u6a21\u5f0f\u5173\u6ce8\u5bf9\u8c61\u4e4b\u95f4\u7684\u901a\u4fe1\u548c\u804c\u8d23\u5206\u914d\u3002<\/p>\n
\u8d23\u4efb\u94fe\u6a21\u5f0f<\/h4>\n
\u8d23\u4efb\u94fe\u6a21\u5f0f\u4f7f\u591a\u4e2a\u5bf9\u8c61\u90fd\u6709\u673a\u4f1a\u5904\u7406\u8bf7\u6c42\uff0c\u4ece\u800c\u907f\u514d\u8bf7\u6c42\u7684\u53d1\u9001\u8005\u548c\u63a5\u6536\u8005\u4e4b\u95f4\u7684\u8026\u5408\u5173\u7cfb\u3002<\/p>\n
class Handler:\n def __init__(self):\n self.next_handler = None\n \n def set_next(self, handler):\n self.next_handler = handler\n return handler\n \n def handle(self, request):\n if self.next_handler:\n return self.next_handler.handle(request)\n return None\n\nclass ConcreteHandler1(Handler):\n def handle(self, request):\n if request == "\u8bf7\u6c421":\n return "\u5904\u7406\u8bf7\u6c421"\n return super().handle(request)\n\nclass ConcreteHandler2(Handler):\n def handle(self, request):\n if request == "\u8bf7\u6c422":\n return "\u5904\u7406\u8bf7\u6c422"\n return super().handle(request)\n\ndef chain_of_responsibility_demo():\n print("\u8d23\u4efb\u94fe\u6a21\u5f0f\u6f14\u793a:")\n \n handler1 = ConcreteHandler1()\n handler2 = ConcreteHandler2()\n handler1.set_next(handler2)\n \n print(handler1.handle("\u8bf7\u6c421"))\n print(handler1.handle("\u8bf7\u6c422"))\n\nchain_of_responsibility_demo()<\/code><\/pre>\n\u547d\u4ee4\u6a21\u5f0f<\/h4>\n
\u547d\u4ee4\u6a21\u5f0f\u5c06\u8bf7\u6c42\u5c01\u88c5\u4e3a\u5bf9\u8c61\uff0c\u4ece\u800c\u53ef\u7528\u4e0d\u540c\u7684\u8bf7\u6c42\u5bf9\u5ba2\u6237\u8fdb\u884c\u53c2\u6570\u5316\u3002<\/p>\n
class Command:\n def execute(self):\n pass\n\nclass Receiver:\n def action(self):\n return "\u6267\u884c\u64cd\u4f5c"\n\nclass ConcreteCommand(Command):\n def __init__(self, receiver):\n self.receiver = receiver\n \n def execute(self):\n return self.receiver.action()\n\nclass Invoker:\n def __init__(self):\n self.command = None\n \n def set_command(self, command):\n self.command = command\n \n def execute_command(self):\n return self.command.execute()\n\ndef command_demo():\n print("\u547d\u4ee4\u6a21\u5f0f\u6f14\u793a:")\n \n receiver = Receiver()\n command = ConcreteCommand(receiver)\n invoker = Invoker()\n \n invoker.set_command(command)\n print(invoker.execute_command())\n\ncommand_demo()<\/code><\/pre>\n\u8fed\u4ee3\u5668\u6a21\u5f0f<\/h4>\n
\u8fed\u4ee3\u5668\u6a21\u5f0f\u63d0\u4f9b\u4e00\u79cd\u65b9\u6cd5\u987a\u5e8f\u8bbf\u95ee\u4e00\u4e2a\u805a\u5408\u5bf9\u8c61\u4e2d\u5404\u4e2a\u5143\u7d20\uff0c\u800c\u53c8\u4e0d\u9700\u66b4\u9732\u8be5\u5bf9\u8c61\u7684\u5185\u90e8\u8868\u793a\u3002<\/p>\n
class Iterator:\n def has_next(self):\n pass\n \n def next(self):\n pass\n\nclass ConcreteIterator(Iterator):\n def __init__(self, collection):\n self.collection = collection\n self.index = 0\n \n def has_next(self):\n return self.index < len(self.collection)\n \n def next(self):\n if self.has_next():\n item = self.collection[self.index]\n self.index += 1\n return item\n return None\n\ndef iterator_demo():\n print("\u8fed\u4ee3\u5668\u6a21\u5f0f\u6f14\u793a:")\n \n collection = [1, 2, 3, 4, 5]\n iterator = ConcreteIterator(collection)\n \n while iterator.has_next():\n print(iterator.next())\n\niterator_demo()<\/code><\/pre>\n\u4e2d\u4ecb\u8005\u6a21\u5f0f<\/h4>\n
\u4e2d\u4ecb\u8005\u6a21\u5f0f\u7528\u4e00\u4e2a\u4e2d\u4ecb\u5bf9\u8c61\u6765\u5c01\u88c5\u4e00\u7cfb\u5217\u7684\u5bf9\u8c61\u4ea4\u4e92\u3002<\/p>\n
class Mediator:\n def send(self, message, colleague):\n pass\n\nclass Colleague:\n def __init__(self, mediator):\n self.mediator = mediator\n \n def send(self, message):\n self.mediator.send(message, self)\n \n def receive(self, message):\n pass\n\nclass ConcreteColleague1(Colleague):\n def receive(self, message):\n return f"\u540c\u4e8b1\u6536\u5230: {message}"\n\nclass ConcreteColleague2(Colleague):\n def receive(self, message):\n return f"\u540c\u4e8b2\u6536\u5230: {message}"\n\nclass ConcreteMediator(Mediator):\n def __init__(self):\n self.colleague1 = None\n self.colleague2 = None\n \n def send(self, message, colleague):\n if colleague == self.colleague1:\n return self.colleague2.receive(message)\n else:\n return self.colleague1.receive(message)\n\ndef mediator_demo():\n print("\u4e2d\u4ecb\u8005\u6a21\u5f0f\u6f14\u793a:")\n \n mediator = ConcreteMediator()\n colleague1 = ConcreteColleague1(mediator)\n colleague2 = ConcreteColleague2(mediator)\n \n mediator.colleague1 = colleague1\n mediator.colleague2 = colleague2\n \n print(colleague1.send("\u4f60\u597d"))\n print(colleague2.send("\u518d\u89c1"))\n\nmediator_demo()<\/code><\/pre>\n\u5907\u5fd8\u5f55\u6a21\u5f0f<\/h4>\n
\u5907\u5fd8\u5f55\u6a21\u5f0f\u5728\u4e0d\u7834\u574f\u5c01\u88c5\u6027\u7684\u524d\u63d0\u4e0b\uff0c\u6355\u83b7\u4e00\u4e2a\u5bf9\u8c61\u7684\u5185\u90e8\u72b6\u6001\u3002<\/p>\n
class Memento:\n def __init__(self, state):\n self.state = state\n\nclass Originator:\n def __init__(self):\n self.state = None\n \n def set_state(self, state):\n self.state = state\n \n def save_state(self):\n return Memento(self.state)\n \n def restore_state(self, memento):\n self.state = memento.state\n\nclass Caretaker:\n def __init__(self):\n self.mementos = []\n \n def add_memento(self, memento):\n self.mementos.append(memento)\n \n def get_memento(self, index):\n return self.mementos[index]\n\ndef memento_demo():\n print("\u5907\u5fd8\u5f55\u6a21\u5f0f\u6f14\u793a:")\n \n originator = Originator()\n caretaker = Caretaker()\n \n originator.set_state("\u72b6\u60011")\n caretaker.add_memento(originator.save_state())\n \n originator.set_state("\u72b6\u60012")\n caretaker.add_memento(originator.save_state())\n \n originator.restore_state(caretaker.get_memento(0))\n print(f"\u6062\u590d\u72b6\u6001: {originator.state}")\n\nmemento_demo()<\/code><\/pre>\n\u89c2\u5bdf\u8005\u6a21\u5f0f<\/h4>\n
\u89c2\u5bdf\u8005\u6a21\u5f0f\u5b9a\u4e49\u5bf9\u8c61\u95f4\u7684\u4e00\u79cd\u4e00\u5bf9\u591a\u7684\u4f9d\u8d56\u5173\u7cfb\uff0c\u5f53\u4e00\u4e2a\u5bf9\u8c61\u7684\u72b6\u6001\u53d1\u751f\u6539\u53d8\u65f6\uff0c\u6240\u6709\u4f9d\u8d56\u4e8e\u5b83\u7684\u5bf9\u8c61\u90fd\u5f97\u5230\u901a\u77e5\u3002<\/p>\n
class Observer:\n def update(self, message):\n pass\n\nclass Subject:\n def __init__(self):\n self.observers = []\n \n def attach(self, observer):\n self.observers.append(observer)\n \n def detach(self, observer):\n self.observers.remove(observer)\n \n def notify(self, message):\n for observer in self.observers:\n observer.update(message)\n\nclass ConcreteObserver(Observer):\n def __init__(self, name):\n self.name = name\n \n def update(self, message):\n return f"{self.name} \u6536\u5230: {message}"\n\ndef observer_demo():\n print("\u89c2\u5bdf\u8005\u6a21\u5f0f\u6f14\u793a:")\n \n subject = Subject()\n observer1 = ConcreteObserver("\u89c2\u5bdf\u80051")\n observer2 = ConcreteObserver("\u89c2\u5bdf\u80052")\n \n subject.attach(observer1)\n subject.attach(observer2)\n \n print(subject.notify("\u65b0\u6d88\u606f"))\n\nobserver_demo()<\/code><\/pre>\n\u72b6\u6001\u6a21\u5f0f<\/h4>\n
\u72b6\u6001\u6a21\u5f0f\u5141\u8bb8\u4e00\u4e2a\u5bf9\u8c61\u5728\u5176\u5185\u90e8\u72b6\u6001\u6539\u53d8\u65f6\u6539\u53d8\u5b83\u7684\u884c\u4e3a\u3002<\/p>\n
class State:\n def handle(self):\n pass\n\nclass ConcreteStateA(State):\n def handle(self):\n return "\u72b6\u6001 A"\n\nclass ConcreteStateB(State):\n def handle(self):\n return "\u72b6\u6001 B"\n\nclass Context:\n def __init__(self):\n self.state = None\n \n def set_state(self, state):\n self.state = state\n \n def request(self):\n return self.state.handle()\n\ndef state_demo():\n print("\u72b6\u6001\u6a21\u5f0f\u6f14\u793a:")\n \n context = Context()\n state_a = ConcreteStateA()\n state_b = ConcreteStateB()\n \n context.set_state(state_a)\n print(context.request())\n \n context.set_state(state_b)\n print(context.request())\n\nstate_demo()<\/code><\/pre>\n\u7b56\u7565\u6a21\u5f0f<\/h4>\n
\u7b56\u7565\u6a21\u5f0f\u5b9a\u4e49\u4e00\u7cfb\u5217\u7b97\u6cd5\uff0c\u628a\u5b83\u4eec\u4e00\u4e2a\u4e2a\u5c01\u88c5\u8d77\u6765\uff0c\u5e76\u4e14\u4f7f\u5b83\u4eec\u53ef\u76f8\u4e92\u66ff\u6362\u3002<\/p>\n
class Strategy:\n def execute(self):\n pass\n\nclass ConcreteStrategyA(Strategy):\n def execute(self):\n return "\u7b56\u7565 A"\n\nclass ConcreteStrategyB(Strategy):\n def execute(self):\n return "\u7b56\u7565 B"\n\nclass Context:\n def __init__(self, strategy):\n self.strategy = strategy\n \n def set_strategy(self, strategy):\n self.strategy = strategy\n \n def execute_strategy(self):\n return self.strategy.execute()\n\ndef strategy_demo():\n print("\u7b56\u7565\u6a21\u5f0f\u6f14\u793a:")\n \n context = Context(ConcreteStrategyA())\n print(context.execute_strategy())\n \n context.set_strategy(ConcreteStrategyB())\n print(context.execute_strategy())\n\nstrategy_demo()<\/code><\/pre>\n\u6a21\u677f\u65b9\u6cd5\u6a21\u5f0f<\/h4>\n
\u6a21\u677f\u65b9\u6cd5\u6a21\u5f0f\u5b9a\u4e49\u4e00\u4e2a\u64cd\u4f5c\u4e2d\u7684\u7b97\u6cd5\u7684\u9aa8\u67b6\uff0c\u800c\u5c06\u4e00\u4e9b\u6b65\u9aa4\u5ef6\u8fdf\u5230\u5b50\u7c7b\u4e2d\u3002<\/p>\n
from abc import ABC, abstractmethod\n\nclass AbstractClass(ABC):\n def template_method(self):\n self.primitive_operation1()\n self.primitive_operation2()\n \n @abstractmethod\n def primitive_operation1(self):\n pass\n \n @abstractmethod\n def primitive_operation2(self):\n pass\n\nclass ConcreteClass(AbstractClass):\n def primitive_operation1(self):\n return "\u64cd\u4f5c1"\n \n def primitive_operation2(self):\n return "\u64cd\u4f5c2"\n\ndef template_method_demo():\n print("\u6a21\u677f\u65b9\u6cd5\u6a21\u5f0f\u6f14\u793a:")\n \n concrete = ConcreteClass()\n concrete.template_method()\n\ntemplate_method_demo()<\/code><\/pre>\n\u8bbf\u95ee\u8005\u6a21\u5f0f<\/h4>\n
\u8bbf\u95ee\u8005\u6a21\u5f0f\u8868\u793a\u4e00\u4e2a\u4f5c\u7528\u4e8e\u67d0\u5bf9\u8c61\u7ed3\u6784\u4e2d\u7684\u5404\u5143\u7d20\u7684\u64cd\u4f5c\u3002<\/p>\n
class Visitor:\n def visit_element_a(self, element):\n pass\n \n def visit_element_b(self, element):\n pass\n\nclass ConcreteVisitor(Visitor):\n def visit_element_a(self, element):\n return f"\u8bbf\u95ee\u5143\u7d20 A: {element.operation_a()}"\n \n def visit_element_b(self, element):\n return f"\u8bbf\u95ee\u5143\u7d20 B: {element.operation_b()}"\n\nclass Element:\n def accept(self, visitor):\n pass\n\nclass ElementA(Element):\n def operation_a(self):\n return "\u5143\u7d20 A \u64cd\u4f5c"\n \n def accept(self, visitor):\n return visitor.visit_element_a(self)\n\nclass ElementB(Element):\n def operation_b(self):\n return "\u5143\u7d20 B \u64cd\u4f5c"\n \n def accept(self, visitor):\n return visitor.visit_element_b(self)\n\ndef visitor_demo():\n print("\u8bbf\u95ee\u8005\u6a21\u5f0f\u6f14\u793a:")\n \n visitor = ConcreteVisitor()\n element_a = ElementA()\n element_b = ElementB()\n \n print(element_a.accept(visitor))\n print(element_b.accept(visitor))\n\nvisitor_demo()<\/code><\/pre>\n\u603b\u7ed3<\/h3>\n
23 \u79cd\u8bbe\u8ba1\u6a21\u5f0f\u5728 Python \u4e2d\u7684\u5b9e\u73b0\u4f53\u73b0\u4e86\u9762\u5411\u5bf9\u8c61\u8bbe\u8ba1\u7684\u7cbe\u9ad3\u3002\u901a\u8fc7\u5b9e\u9645\u573a\u666f\u7684\u843d\u5730\u5e94\u7528\uff0c\u6211\u4eec\u53ef\u4ee5\u66f4\u597d\u5730\u7406\u89e3\u6bcf\u79cd\u6a21\u5f0f\u7684\u9002\u7528\u573a\u666f\u548c\u5b9e\u73b0\u65b9\u5f0f\u3002<\/p>\n
\u638c\u63e1\u8bbe\u8ba1\u6a21\u5f0f\u4e0d\u4ec5\u80fd\u591f\u63d0\u9ad8\u4ee3\u7801\u7684\u53ef\u7ef4\u62a4\u6027\u548c\u53ef\u6269\u5c55\u6027\uff0c\u8fd8\u80fd\u5e2e\u52a9\u5f00\u53d1\u8005\u66f4\u597d\u5730\u7406\u89e3\u548c\u5e94\u7528\u9762\u5411\u5bf9\u8c61\u8bbe\u8ba1\u539f\u5219\u3002\u5728\u5b9e\u9645\u9879\u76ee\u4e2d\uff0c\u5408\u7406\u4f7f\u7528\u8bbe\u8ba1\u6a21\u5f0f\u53ef\u4ee5\u5927\u5927\u63d0\u9ad8\u4ee3\u7801\u8d28\u91cf\u548c\u5f00\u53d1\u6548\u7387\u3002<\/p>\n