Python 3.4 : can static methods only be called from an instance?

Question

I am trying to call a @staticmethod method from within a class to initialize a class variable as shown here :

class Test:
    @staticmethod
   def get_bit_count():
       return 8
   num = get_bit_count()

But this immediately throws the following error : TypeError: 'staticmethod' object is not callable.

However, the following code works just fine :

class Test:
    @staticmethod
    def get_bit_count():
        return 8
    num = None
    def __init__(self):
        self.num = self.get_bit_count()

print(Test.get_bit_count())
print(Test().num)

The method can be called and the variable num gets set correctly with the following output :

8
8

But with that code I now need to instantiate the class to do so.

Is there a way to allow me to use Test.num and get 8 not None without instantiating the class ? I wish to do so to avoid redundancy by having only one variable in the method get_bit_count() to change when I whish to update my code.

Answer 1

Static methods, as stated in the documentation for staticmethod can only be called on the class or an instance.

You could use a normal method, though. If you want to be able to call it also on an instance, just let it accept any number of arguments:

class Test:
    def get_bit_count(*args, **kwargs):
        return 8

    num = get_bit_count()


print(Test.num)
# 8

t = Test()
print(t.get_bit_count())
# 8