Code Breakdown of the Vehicle Class

Overview

The provided code snippet defines a base class called Vehicle and a derived class called bus. It demonstrates fundamental principles of object-oriented programming (OOP) such as inheritance and class attributes in Python.

Code Structure

1. Class Definition

class Vehicle():
    model='nano'
    year=2000

• Vehicle Class: This class is a blueprint for creating vehicle objects.
• Class Attributes: model and year are attributes associated with the class rather than instances of the class. They have default values of 'nano' and 2000, respectively.

2. Constructor Method

def __init__(self, model, year):
    self.model = model
    self.year = year

• __init__ Method: This is the constructor method that is automatically called when an instance of the class is created.
• Parameters: It takes two parameters, model and year, which are used to initialize instance attributes.
• Instance Attributes: self.model and self.year are assigned the values of the parameters, allowing each instance of Vehicle to have its own specific model and year.

3. Derived Class

class bus(Vehicle):
    pass

• Inheritance: The bus class inherits from the Vehicle class, which means it can access the attributes and methods of Vehicle.
• Empty Body with pass: The pass statement indicates that no additional attributes or methods are defined in bus at this time. It serves as a placeholder.

4. Instantiation of Object

a = bus("bus", 2000)

• Object Creation: This line creates an instance of the bus class named a, with the model "bus" and year 2000. However, since there are no specific methods or attributes in bus, it simply inherits from Vehicle.

5. Accessing and Printing Attributes

print("model and year is ", Vehicle.model, Vehicle.year)

• Accessing Class Attributes: This line accesses the class attributes model and year of the Vehicle class directly and prints them. The output will always be "nano" and 2000, regardless of any specific instance of Vehicle or bus.

Key Concepts Explained

• Class vs. Instance: Class attributes belong to the class itself, while instance attributes belong to each object created from the class. Here, model and year are class attributes, and self.model and self.year represent instance attributes.

• Inheritance: The bus class inherits from the Vehicle class, allowing it to use the functionality defined in Vehicle. Future extensions to bus can include methods or override inherited methods.

Additional Examples

Example of overriding the __init__ method in the bus class:

class bus(Vehicle):
    def __init__(self, model, year, capacity):
        super().__init__(model, year)  # Call constructor of Vehicle
        self.capacity = capacity

• Here, bus has its own __init__ method, allowing it to initialize a new attribute capacity along with model and year.

Example of adding a method to Vehicle:

class Vehicle():
    ...
    def display_info(self):
        return f"Model: {self.model}, Year: {self.year}"

• The display_info method provides a way for vehicle instances to return their details in a formatted string.

Conclusion

The provided code snippets demonstrate the basics of class creation, inheritance, and initialization in Python. Understanding the distinction between class and instance attributes, as well as the flow of object instantiation, is essential for leveraging OOP concepts effectively in Python programming. For further learning on advanced topics in object-oriented programming and data analysis, consider exploring the resources available on the Enterprise DNA Platform.