Python Programming

70053 Autumn Term 2021/2022

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Advanced Lesson 3

Advanced Object-Oriented Programming

Chapter 4: Class attributes and methods

Static methods

face Josiah Wang

To further complicate things, Python also offers a static method. This basically acts like a normal function, except that it is defined inside the scope of a class. Note that there is no compulsory first parameter self or cls here - it’s just a normal function! Like a class method, use a @staticmethod decorator to make a method static; this tells Python not to pass self or cls as the first argument in the method call.

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

    @staticmethod
    def calculate_sum(num1, num2):
        return num1 + num2

total = Person.calculate_sum(5, 3)
print(total)

So, when you have a method that does not need any information from either cls or self, but can still be part of the class, then this could be a static method instead.

In my personal opinion, there is really not too many uses for static methods. Honestly, I struggled to come up with the example above, and it’s still not convincing! The only reason to use it is to group related functions inside the scope of a class. For example, you can have a Calculation class that has static methods like sum(), product(), exp() etc. In any case, it is enough that you know that @staticmethod exists!