classmethod() Function in Python

Python classmethod() Function

The classmethod() function in Python is a built-in method that belongs to the classmethod descriptor type. It is used to define a method within a class that can be called on the class itself, rather than on an instance of the class.

To define a class method, you use the @classmethod decorator before the method definition. The method receives the class itself as the first parameter, conventionally named cls, instead of the instance (usually self).

Here's an example that demonstrates the usage of the classmethod() function:

class MyClass:
    @classmethod
    def class_method(cls, arg1, arg2):
        # Use the class and its arguments
        print("Class method called")
        print("Class:", cls)
        print("Arguments:", arg1, arg2)

# Calling the class method on the class itself
MyClass.class_method("Hello", "World")

In this example, the class_method() method is defined as a class method using the @classmethod decorator. When the method is called on the class itself (MyClass.class_method()), it receives the class object (MyClass) as the first argument (cls), along with any additional arguments you provide (arg1 and arg2 in this case). Inside the method, you can access the class and its arguments as needed.

The output of the above code will be:

Class method called
Class: <class '__main__.MyClass'>
Arguments: Hello World

Note that class methods are often used to create alternative constructors or to perform operations that involve the class itself, rather than individual instances of the class.