Python operator overloading with examples

Python operator overloading, allows you to define the behavior of operators (+, -, *, /, etc.) for objects of custom classes. By implementing special methods or dunder methods (double underscore methods), you can customize how operators work with your objects.

Here are a few examples of operator overloading in Python:

Addition Operator (+):

class Point:
    def __init__(self, x, y):
        self.x = x
        self.y = y

    def __add__(self, other):
        if isinstance(other, Point):
            return Point(self.x + other.x, self.y + other.y)
        elif isinstance(other, (int, float)):
            return Point(self.x + other, self.y + other)
        else:
            raise TypeError("Unsupported operand type.")

# Create two Point objects
p1 = Point(1, 2)
p2 = Point(3, 4)

# Add two Point objects
p3 = p1 + p2
print(p3.x, p3.y)  # Output: 4, 6

# Add a Point object with an integer
p4 = p1 + 5
print(p4.x, p4.y)  # Output: 6, 7

In the example above, the Point class defines the __add__ method, which is called when the + operator is used with Point objects. It allows adding two Point objects together by combining their x and y coordinates. It also supports adding an integer or float to a Point object by adding the value to both the x and y coordinates.

String Representation (str):

class Person:
    def __init__(self, name, age):
        self.name = name
        self.age = age

    def __str__(self):
        return f"Person(name={self.name}, age={self.age})"

# Create a Person object
person = Person("Alice", 25)

# Display the object as a string
print(person)  # Output: Person(name=Alice, age=25)

In the example above, the Person class defines the __str__ method, which is called when the str() function is used or when the object is converted to a string implicitly. It returns a formatted string representation of the Person object.

Comparison Operators (==, !=, >, <, >=, <=):

class Rectangle:
    def __init__(self, length, width):
        self.length = length
        self.width = width

    def __eq__(self, other):
        if isinstance(other, Rectangle):
            return self.length == other.length and self.width == other.width
        else:
            return False

# Create two Rectangle objects
rect1 = Rectangle(5, 10)
rect2 = Rectangle(5, 10)
rect3 = Rectangle(3, 6)

# Compare two Rectangle objects
print(rect1 == rect2)  # Output: True
print(rect1 == rect3)  # Output: False

In the example above, the Rectangle class defines the __eq__ method, which is called when the == an operator is used with Rectangle objects. It compares the length and width attributes of two rectangles and returns True if they are equal.