Can you explain the essence of the 'Factory' pattern and its main advantages?

The "Factory" pattern is a creational design pattern that provides an interface for creating objects but allows subclasses to decide which class to instantiate. In other words, object creation is delegated to a separate method or class.

Main advantages:

• Allows creating objects without specifying the exact class, increasing flexibility and extensibility of the code.
• Simplifies replacing and adding new types of objects without changing client code.
• Reduces coupling between classes, improving support and testing.

Example in Python:

class Animal:
    def speak(self):
        pass

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

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

class AnimalFactory:
    @staticmethod
    def create_animal(animal_type):
        if animal_type == "dog":
            return Dog()
        elif animal_type == "cat":
            return Cat()
        else:
            raise ValueError("Unknown animal type")

# Usage
animal = AnimalFactory.create_animal("dog")
print(animal.speak())  # Output: Woof