🔧 Adding

Composite Pattern

Author: raj713335

05 Structural Design Patterns/03 Composite Design Pattern.py

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+# Composite Pattern Python Implementation: Products and Boxes
+
+from abc import ABC, abstractmethod
+
+
+# Component Interface
+
+class Item(ABC):
+    @abstractmethod
+    def get_price(self):
+        ...
+
+    @abstractmethod
+    def get_description(self):
+        ...
+
+
+# Leaf Class: Product
+
+class Product(Item):
+    def __init__(self, name, price):
+        self.name = name
+        self.price = price
+
+    def get_price(self):
+        return self.price
+
+    def get_description(self):
+        return f"Product: {self.name} (${self.price})"
+
+
+# Composite Class: Box
+
+class Box(Item):
+    def __init__(self, name):
+        self.name = name
+        self.items = []
+
+    def add(self, item: Item):
+        self.items.append(item)
+
+    def remove(self, item: Item):
+        self.items.remove(item)
+
+    def get_price(self):
+        total = 0
+
+        for item in self.items:
+            total += item.get_price()
+        return total
+
+    def get_description(self):
+        description = [item.get_description() for item in self.items]
+        return f"Box: {self.name} containing:\n " + "\n ".join(description)
+
+
+# client Code
+
+if __name__ == "__main__":
+    # Leaf Products
+    pen = Product("Pen", 2.5)
+    notebook = Product("Notebook", 5.0)
+    charger = Product("Charger", 15.0)
+
+    # Small Box
+    small_box = Box("Stationary Box")
+    small_box.add(pen)
+    small_box.add(notebook)
+
+    # Another box
+
+    electronics_box = Box("Electronics Box")
+    electronics_box.add(charger)
+
+    # Big Box
+
+    main_box = Box("Main Box")
+    main_box.add(small_box)
+    main_box.add(electronics_box)
+    main_box.add(Product("USB Drive", 8.0))
+
+    print(main_box.get_description())
+    print(f"Total Price: ${main_box.get_price()}")