Master Python OOP: Classes, Objects, Getters, Setters, and Property Decorators

What is Python? According to its creator Guido van Rossum, Python is a high‑level programming language designed for code readability and concise syntax.

Python is valued for its elegant, natural coding style and its versatility across data science, web development, and machine learning.

Classes and Objects

In object‑oriented programming, an object represents a real‑world entity (e.g., a car) with data (attributes) and behavior (methods). A class serves as a blueprint for creating objects of the same type.

Defining a Class

class Vehicle:
    pass

Instantiating the class creates an object:

car = Vehicle()
print(car)  # <__main__.Vehicle object at 0x...>

Constructor and Attributes

The __init__ method initializes an object’s attributes such as number of wheels, tank type, seating capacity, and maximum velocity.

class Vehicle:
    def __init__(self, number_of_wheels, type_of_tank, seating_capacity, maximum_velocity):
        self.number_of_wheels = number_of_wheels
        self.type_of_tank = type_of_tank
        self.seating_capacity = seating_capacity
        self.maximum_velocity = maximum_velocity

Creating a specific vehicle:

tesla_model_s = Vehicle(4, 'electric', 5, 250)

Methods, Getters, and Setters

Methods provide behavior. Simple getter and setter methods can be written as:

def number_of_wheels(self):
    return self.number_of_wheels

def set_number_of_wheels(self, number):
    self.number_of_wheels = number

Python’s @property decorator offers a more idiomatic way:

class Vehicle:
    def __init__(...):
        ...

    @property
    def number_of_wheels(self):
        return self._number_of_wheels

    @number_of_wheels.setter
    def number_of_wheels(self, number):
        self._number_of_wheels = number

Using the property:

print(tesla_model_s.number_of_wheels)  # 4
tesla_model_s.number_of_wheels = 2
print(tesla_model_s.number_of_wheels)  # 2

Additional Example Method

A custom method can perform actions, such as emitting a sound:

def make_noise(self):
    print('VRUUUUUUUM')

Calling it:

tesla_model_s.make_noise()  # VRUUUUUUUM