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Sayandeep Majumdar
Sayandeep Majumdar

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Mastering Python's Classes and Objects : Beginners

Introduction:

Python, known for its simplicity and versatility, is a popular programming language used for various applications, from web development to data analysis. One of the key features that sets Python apart is its support for object-oriented programming (OOP). In this blog post, we will dig into the world of Python classes and objects and explore how they enable us to create reusable and modular code. Before this you've already know the basic of python programming language.

Understanding Classes

In Python, a class is a blueprint or a template for creating objects. It defines a collection of attributes (variables) and methods (functions) that characterize any object instantiated from it. The structure of a class consists of a class name, attributes, and methods.

Let's start by creating a simple class called "Car":


class Car:
    def __init__(self, brand, model, color):
        self.brand = brand
        self.model = model
        self.color = color

    def start_engine(self):
        print(f"The {self.brand} {self.model}'s engine is running.")

    def stop_engine(self):
        print(f"The {self.brand} {self.model}'s engine is stopped.")

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In the example above, we define the "Car" class with three attributes: "brand," "model," and "color." We also have two methods, "start_engine()" and "stop_engine()".

Creating Objects (Instances)

Once we have defined a class, we can create instances of that class, known as objects. Each object has its own set of attributes and can invoke the methods defined in the class. To create an object, we call the class as if it were a function:

my_car = Car("Toyota", "Camry", "Blue")

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Here, we create an instance of the "Car" class called "my_car" with the brand "Toyota," model "Camry," and color "Blue."

Accessing Attributes and Invoking Methods

To access the attributes of an object, we use the dot notation:

print(my_car.brand)   # Output: Toyota
print(my_car.model)   # Output: Camry
print(my_car.color)   # Output: Blue

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Similarly, we can invoke the methods of an object using the dot notation:

my_car.start_engine()     # Output: The Toyota Camry's engine is running.
my_car.stop_engine()      # Output: The Toyota Camry's engine is stopped.

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Inheritance and Polymorphism

Inheritance is another crucial aspect of object-oriented programming. It allows us to create a new class (derived class or subclass) based on an existing class (base class or superclass). The derived class inherits all the attributes and methods of the base class and can extend or modify them as needed.

Consider the following example:

class ElectricCar(Car):
    def __init__(self, brand, model, color, battery_capacity):
        super().__init__(brand, model, color)
        self.battery_capacity = battery_capacity

    def display_battery_capacity(self):
        print(f"The {self.brand} {self.model} has a battery capacity of {self.battery_capacity} kWh.")

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In this case, the "ElectricCar" class inherits from the "Car" class and adds a new attribute "battery_capacity" and a method "display_battery_capacity()".

Polymorphism, on the other hand, allows objects of different classes to be used interchangeably when they share a common interface or base class. This concept enables code reuse and flexibility in Python.

Conclusion

Python's support for classes and objects empowers developers to write clean, modular, and reusable code. Classes provide a blueprint for creating objects, and objects allow us to encapsulate data and behavior together. Through inheritance and polymorphism, we can build complex class hierarchies and leverage code reuse effectively.

By understanding the fundamentals of classes and objects in Python, you can unlock the power of object-oriented programming and create elegant and efficient solutions for a wide range of programming tasks.

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