Cache the result of a function as a pickle dump so we don't have to load it again the next time we want to use it.

cache_in_file.py

def cache_in_file(filepath, object_creation_function):
    if os.path.exists(filepath):
        with open(filepath, "r") as dump_file:
            obj = pickle.load(dump_file)
    else:
        obj = object_creation_function()
        with open(filepath, "w") as dump_file:
            pickle.dump(obj, dump_file)
    return obj