from methodtools import lru_cache

class A(object):

    # cached method. the storage lifetime follows `self` object
    @lru_cache()
    def cached_method(self, args):
        ...

    # cached classmethod. the storage lifetime follows `A` class
    @lru_cache()  # the order is important!
    @classmethod  # always lru_cache on top of classmethod
    def cached_classmethod(self, args):
        ...

    # cached staticmethod. the storage lifetime follows `A` class
    @lru_cache()  # the order is important!
    @staticmethod  # always lru_cache on top of staticmethod
    def cached_staticmethod(self, args):
        ...

@lru_cache()  # just same as functools.lru_cache
def cached_function():
    ...