A decorator of functions that stores a dictionary *args->result in a pickle and returns cached versions after first call

cache.py

import os
import pickle


def cache(file_name):
    """
    A decorator to cache the result of the function into a file. The result
    must be a dictionary. The result storage is in pickle
    """
    def cache_function(function):
        cache = {}
        if os.path.exists(file_name):
            # print('reading cache file')
            with open(file_name, 'rb') as f:
                cache = pickle.load(f)

        def func_wrapper(*args, **kwargs):
            unique = (repr(args), repr(tuple(kwargs)))

            if unique not in cache:
                # print('update cache')
                cache[unique] = function(*args, **kwargs)
                # update the cache file
                with open(file_name, 'wb') as f:
                    pickle.dump(cache, f)
            else:
                # print('using cache file')
                pass

            return cache[unique]

        return func_wrapper

    return cache_function


if __name__ == '__main__':

    @cache('bla.pkl')
    def bla(a, b):
        return a + b

    bla(1, 2)  # store result in 'bla.pkl'
    bla(1, 2)  # return cached result