Why do we use @staticmethod?

Question

I just can\'t see why do we need to use @staticmethod. Let\'s start with an exmaple.

class test1:
    def __init__(self,value):
        self.value=value

            


        

Answer 1

I will add something other answers didn't mention. It's not only a matter of modularity, of putting something next to other logically related parts. It's also that the method could be non-static at other point of the hierarchy (i.e. in a subclass or superclass) and thus participate in polymorphism (type based dispatching). So if you put that function outside the class you will be precluding subclasses from effectively overriding it. Now, say you realize you don't need self in function C.f of class C, you have three two options:

1. Put it outside the class. But we just decided against this.

2. Do nothing new: while unused, still keep the self parameter.

3. Declare you are not using the self parameter, while still letting other C methods to call f as self.f, which is required if you wish to keep open the possibility of further overrides of f that do depend on some instance state.

Option 2 demands less conceptual baggage (you already have to know about self and methods-as-bound-functions, because it's the more general case). But you still may prefer to be explicit about self not being using (and the interpreter could even reward you with some optimization, not having to partially apply a function to self). In that case, you pick option 3 and add @staticmethod on top of your function.