Can you explain the main ideas behind object-oriented programming?

Object-oriented programming (OOP) is based on several key ideas:

• Classes and objects: A class is a template or description of an entity, and an object is a specific instance of that class with its own data.
• Encapsulation: Hiding the internal implementation of an object and providing access to data through methods, which protects data from improper use.
• Inheritance: Allows creating new classes based on existing ones, inheriting their properties and methods, which promotes code reuse.
• Polymorphism: The ability of objects of different classes to respond to the same messages (method calls) in different ways, simplifying code extension and maintenance.

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"

animals = [Dog(), Cat()]
for animal in animals:
    print(animal.speak())  # Will output "Woof" and "Meow"