**Course Title:** Modern Python Programming: Best Practices and Trends **Section Title:** Object-Oriented Programming (OOP) in Python **Topic:** Introduction to Object-Oriented Programming: Classes, objects, and methods. **Introduction to Object-Oriented Programming (OOP)** Object-Oriented Programming (OOP) is a programming paradigm that revolves around the concept of "objects" that have properties and methods. OOP is a powerful tool for writing efficient, readable, and maintainable code. In this topic, we will cover the basics of OOP in Python, including classes, objects, and methods. **What are Classes?** In Python, a class is a blueprint or a template that defines the properties and behavior of an object. A class is essentially a design pattern or a template that defines the characteristics of an object. You can think of a class as a template or a blueprint that defines the properties and behavior of an object. **Defining a Class** In Python, you can define a class using the `class` keyword followed by the name of the class. Here's an example of a simple class: ```python class Dog: pass ``` In this example, we defined a class called `Dog`. We didn't add any properties or methods to the class, but we'll get to that later. **What are Objects?** An object is an instance of a class. You can think of an object as a real-world entity that has properties and behavior. In Python, you can create an object by instantiating a class. Here's an example: ```python class Dog: pass my_dog = Dog() ``` In this example, we created an object called `my_dog` that is an instance of the `Dog` class. **Defining Properties** In Python, you can define properties in a class using variables that are defined inside the class. Here's an example: ```python class Dog: def __init__(self, name, age): self.name = name self.age = age my_dog = Dog("Max", 3) print(my_dog.name) # Output: Max print(my_dog.age) # Output: 3 ``` In this example, we defined a class called `Dog` that has two properties: `name` and `age`. We used the `__init__` method to initialize the properties when an object is created. **Defining Methods** In Python, you can define methods in a class using functions that are defined inside the class. Here's an example: ```python class Dog: def __init__(self, name, age): self.name = name self.age = age def bark(self): print("Woof!") my_dog = Dog("Max", 3) my_dog.bark() # Output: Woof! ``` In this example, we defined a class called `Dog` that has a method called `bark`. We used the `bark` method to make the dog bark. **Access Modifiers** In Python, you can use access modifiers to control access to properties and methods in a class. Here's an example: ```python class Dog: def __init__(self, name, age): self.__name = name self.__age = age def get_name(self): return self.__name my_dog = Dog("Max", 3) print(my_dog.get_name()) # Output: Max ``` In this example, we used the `__` prefix to make the `name` property private. We then used a method called `get_name` to access the private property. **Conclusion** In this topic, we covered the basics of Object-Oriented Programming (OOP) in Python. We learned about classes, objects, properties, methods, and access modifiers. We also saw examples of how to define classes, create objects, and access properties and methods. **Key Takeaways** * A class is a blueprint or template that defines the properties and behavior of an object. * An object is an instance of a class. * You can define properties in a class using variables that are defined inside the class. * You can define methods in a class using functions that are defined inside the class. * You can use access modifiers to control access to properties and methods in a class. **Practical Exercise** 1. Define a class called `Car` that has properties for `brand`, `model`, and `year`. 2. Create an object of the `Car` class and print the properties. 3. Add a method to the `Car` class that prints a message when the car starts. 4. Use the `__` prefix to make the `brand` property private and create a method to access it. **Additional Resources** * [Python Documentation - Classes](https://docs.python.org/3/tutorial/classes.html) * [W3Schools - Python Classes](https://www.w3schools.com/python/python_classes.asp) * [Real Python - Object-Oriented Programming in Python](https://realpython.com/python-object-oriented-programming/) **Leave a Comment** Please leave a comment if you have any questions or need further clarification on any of the topics covered in this lesson.