What are static and class methods?

Regular method (instance method):

Receives a reference to the instance (self) as its first argument:

class MyClass:
    def instance_method(self):
        return f"Called for {self}"

@classmethod — a method of the class:

Receives a reference to the class (cls) instead of an instance:

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

    @classmethod
    def from_string(cls, data_string):
        name, age = data_string.split(",")
        return cls(name, int(age))

# Alternative constructor
user = User.from_string("Anna,25")
print(user.name)  # Anna

@staticmethod — a static method:

Receives neither self nor cls. It behaves like a regular function placed inside a class namespace:

class MathUtils:
    @staticmethod
    def is_even(n):
        return n % 2 == 0

print(MathUtils.is_even(4))  # True

When to use which:

• Instance method — when you need access to the object's attributes (self).
• @classmethod — for alternative constructors or when modifying class attributes.
• @staticmethod — for utility functions that logically belong to the class but do not need access to the instance or the class.