12-3. Method Overloading and Overriding

Method Overloading

Method overloading is a feature in some programming languages where multiple methods can have the same name but differ in the number or type of their parameters. However, Python does not support method overloading in the same way as languages like Java or C++. Instead, Python allows default parameter values and variable-length arguments to achieve similar behavior.

Example of Method Overloading (Conceptually)

Although Python does not support method overloading directly, you can achieve similar behavior using default parameters or variable-length arguments.

In this example, the add method can be called with either two or three arguments.

Method Overriding

Method overriding occurs when a subclass provides a specific implementation for a method that is already defined in its superclass. The subclass method replaces the superclass method.

Example of Method Overriding

Let’s consider the previous example with Car, RV, and Truck classes to demonstrate method overriding.

class Car:
    def __init__(self, make="", model="", year=0):
        self.make = make
        self.model = model
        self.year = year

def print_info(self):
        print(f"A {self.year} {self.make} {self.model}. Impressed?")

class RV(Car):
    def __init__(self, make, model, year, rv_type):
        super().__init__(make, model, year)
        self.rv_type = rv_type

def print_info(self):  # Overriding the print_info method
        print(f"A {self.year} {self.make} {self.model} RV of type {self.rv_type}. Impressed?")

class Truck(Car):
    def __init__(self, make, model, year, capacity):
        super().__init__(make, model, year)
        self.capacity = capacity

def print_info(self):  # Overriding the print_info method
        print(f"A {self.year} {self.make} {self.model} Truck with a capacity of {self.capacity} tons. Impressed?")

# Creating objects
my_rv = RV("Winnebago", "Vista", 2021, "Class A")
my_truck = Truck("Ford", "F-150", 2022, 3)

# Calling the overridden methods
my_rv.print_info()  # Output: A 2021 Winnebago Vista RV of type Class A. Impressed?
my_truck.print_info()  # Output: A 2022 Ford F-150 Truck with a capacity of 3 tons. Impressed?

Key Differences

Method Overloading: Allows multiple methods with the same name but different parameters. Python handles this through default arguments and variable-length arguments since it doesn’t support traditional overloading.
Method Overriding: Allows a subclass to provide a specific implementation for a method already defined in its superclass. The subclass method replaces the superclass method when called on an instance of the subclass.

Last updated: April 22, 2025

Python Programming

12-3. Method Overloading and Overriding