How Do Class Variables and Methods Work in Python?

Understanding Class-Level Variables and Methods in Python

Creating static variables or methods, often referred to as class variables or class methods, is a useful concept in programming. In Python, class-level variables and methods provide a way to define shared properties or functionalities for a class.

Creating Class Variables

To create a class variable, simply declare it within the class definition but outside any method. For example:

class MyClass:
    i = 3

This creates a class-level variable named i with a value of 3.

Accessing Class Variables

Class variables can be accessed using the class name followed by a dot (.) notation. For instance, to retrieve the value of i from the above class:

MyClass.i  # Output: 3

Class Variables vs. Instance Variables

Class variables are distinct from instance-level (or non-static) variables, which are declared within a method. As a result, you can have both class-level and instance-level variables with the same name within a class.

Creating Class Methods

Class methods are methods that are bound to the class itself, not to specific instances of the class. To create a class method, use the @staticmethod decorator:

class C:
    @staticmethod
    def f(arg1, arg2, ...): ...

Using Class Methods

Class methods can be invoked using the class name followed by a dot notation, similar to class variables. Class methods provide a way to define common functionality that can be shared across all instances of the class and provide a convenient way to perform operations or transformations.

Class Methods vs. Static Methods

Python doesn't have static methods in the traditional sense like other languages. @staticmethod methods in Python are still slightly bound to the class, unlike static methods in Java or C . However, it's generally recommended to use class methods classmethod instead, as they allow the method to receive the class type as the first argument.

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