Using static methods in python - best practice

Question

When and how are static methods suppose to be used in python? We have already established using a class method as factory method to create an instance of an object should be

Answer 1

Here is a decent use case for @staticmethod.

I have been working on a game as a side project. Part of that game includes rolling dice based on stats, and the possibility of picking up items and effects that impact your character's stats (for better or worse).

When I roll the dice in my game, I need to basically say... take the base character stats and then add any inventory and effect stats into this grand netted figure.

You can't take these abstract objects and add them without instructing the program how. I'm not doing anything at the class level or instance level either. I didn't want to define the function in some global module. The last best option was to go with a static method for adding up stats together. It just makes the most sense this way.

class Stats:

    attribs = ['strength', 'speed', 'intellect', 'tenacity']

    def __init__(self,
                 strength=0,
                 speed=0,
                 intellect=0,
                 tenacity=0
                 ):
        self.strength = int(strength)
        self.speed = int(speed)
        self.intellect = int(intellect)
        self.tenacity = int(tenacity)

    # combine adds stats objects together and returns a single stats object
    @staticmethod
    def combine(*args: 'Stats'):
        assert all(isinstance(arg, Stats) for arg in args)
        return_stats = Stats()
        for stat in Stats.attribs:
            for _ in args:
                setattr(return_stats, stat,
                        getattr(return_stats, stat) + getattr(_, stat))
        return (return_stats)

Which would make the stat combination calls work like this

a = Stats(strength=3, intellect=3)
b = Stats(strength=1, intellect=-1)
c = Stats(tenacity=5)
print(Stats.combine(a, b, c).__dict__)

{'strength': 4, 'speed': 0, 'intellect': 2, 'tenacity': 5}