Creational Patterns

• Factory Design Pattern
• Builder
• Singleton
  Purpose: Deal with object creation mechanisms, trying to abstract the instantiation process

Examples:

• Abstract Factory: Provide an interface for creating families of related objects without specifying concrete classes
• Builder: Separate construction of complex objects from their representation
• Factory Method: Define an interface for creating objects, but let subclasses decide which class to instantiate
• Prototype: Create new objects by copying a prototypical instance
• Singleton: Ensure a class has only one instance with global access

Code Example - Factory Pattern

class Animal:
    def speak(self):
        pass

class Dog(Animal):
    def speak(self):
        return "Woof!"

class Cat(Animal):
    def speak(self):
        return "Meow!"

def animal_factory(animal_type):
    if animal_type == "dog":
        return Dog()
    elif animal_type == "cat":
        return Cat()

# Usage
pet = animal_factory("dog")
print(pet.speak())  # Output: Woof!