9. Static methods

Static methods behave like regular functions and are included in the class since they have some logical connection with it.

Choose to use static methods when there are no references to instance variables or class variables within it.

In practice, use static methods to define utility methods or group functions that have some logical relationships in a class.

Static methods do not pass anything automatically (such as self or cls).

Static methods cannot access and modify an object’s attributes.

In comparison, instance methods pass self automatically.

In comparison, class methods pass the cls automatically.

Static methods do not require a class instance to be created first.

The simplified code below illustrates this:

class LevelGame:

    @staticmethod
    def get_required_level_score(game_level):
        return game_level * 10

score = LevelGame.get_required_level_score(game_level=3)
print(score)

In the code below, when the game is instantiated at a particular game level, game = LevelGame(game_level=1), it will use the static method, get_required_level_score, and then print the value for it.

def get_required_level_score(level): does not pass in self to the function.

The decorator, @staticmethod, is needed to make it so that the function does not require self to be passed in.

class LevelGame:
    game_lives = 5

    def __init__(self, game_level):
        self.game_level = game_level
        print(self.get_required_level_score(self.game_level))

    @staticmethod
    def get_required_level_score(level):
        return level * 10

game = LevelGame(game_level=1)

Tasks

1. Test out the static method and show that it is working for 2 different game levels.

2. Write a static method that calculates a level bonus score using the formula: bonus = level * 5.

Note

If a static method needs to call another static method, since self is not avalailable to the method, a reference to the class is needed.

The class itself can be used or the special method, __class__, can be used.

e.g return MyClass.staticmethod2()

e.g return __class__.staticmethod2()