Class method vs static method in Python

Python Programming Server Side Programming

The class method in Python is a method, which is bound to the class but not the object of that class. The static methods are also same but there are some basic differences. For class methods, we need to specify @classmethod decorator, and for static method @staticmethod decorator is used.

Syntax for Class Method.

class my_class:
   @classmethod
  deffunction_name(cls, arguments):
      #Function Body
      return value

Syntax for Static Method.

class my_class:
   @staticmethod
   deffunction_name(arguments):
      #Function Body
      return value

What are the differences between Classmethod and StaticMehtod?

Class Method	Static Method
The class method takes cls (class) as first argument.	The static method does not take any specific parameter.
Class method can access and modify the class state.	Static Method cannot access or modify the class state.
The class method takes the class as parameter to know about the state of that class.	Static methods do not know about class state. These methods are used to do some utility tasks by taking some parameters.
@classmethod decorator is used here.	@staticmethod decorator is used here.

The Static methods are used to do some utility tasks, and class methods are used for factory methods. The factory methods can return class objects for different use cases.

Example code

from datetime import date as dt
class Employee:
   def __init__(self, name, age):
      self.name = name
      self.age = age
   @staticmethod
   defisAdult(age):
      if age > 18:
         return True
      else:
         return False
   @classmethod
   defemp_from_year(emp_class, name, year):
      return emp_class(name, dt.today().year - year)
   def __str__(self):
      return 'Employee Name: {} and Age: {}'.format(self.name, self.age)
e1 = Employee('Dhiman', 25)
print(e1)
e2 = Employee.emp_from_year('Subhas', 1987)
print(e2)
print(Employee.isAdult(25))
print(Employee.isAdult(16))

Output

Employee Name: Dhiman and Age: 25
Employee Name: Subhas and Age: 31
True
False

Karthikeya Boyini

Published on 23-Nov-2018 06:25:40

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