Python __eq__ method

In Python, the __eq__ method is a special method that is used to define how two objects of a class should be compared for equality. This method is called when the == operator is used to compare two objects of the class. The __eq__ method should return True if the objects are considered equal, and False otherwise.

Here’s an example of how the __eq__ method can be used in Python:

class Point:
    def __init__(self, x, y):
        self.x = x
        self.y = y
    
    def __eq__(self, other):
        if isinstance(other, Point):
            return self.x == other.x and self.y == other.y
        return False
    
p1 = Point(1, 2)
p2 = Point(1, 2)
p3 = Point(2, 3)

print(p1 == p2)  # Output: True
print(p1 == p3)  # Output: False

In this example, we define a Point class with two attributes: x and y. We also define an __eq__ method that compares two Point objects for equality based on their x and y attributes.

When we create two Point objects with the same x and y values and compare them using the == operator, the __eq__ method is called and returns True because the objects are considered equal. When we create two Point objects with different x and y values and compare them using the == operator, the __eq__ method is called and returns False because the objects are not considered equal.

Note that the __eq__ method can be used in conjunction with other comparison operators (e.g. !=, <, <=, >, >=) by defining other special methods like __ne__, __lt__, __le__, __gt__, and __ge__. These methods allow you to define how two objects of a class should be compared for inequality and ordering.