using decorators to persist python objects

Code that I got from below link, can persist data to the disk.

http://tohyongcheng.github.io/python/2016/06/07/persisting-a-cache-in-python-to-disk.html

I tried it but the file does not get generated.

import atexit
import pickle
# or import cPickle as pickle

def persist_cache_to_disk(filename):
    def decorator(original_func):
        try:
            cache = pickle.load(open(filename, 'r'))
        except (IOError, ValueError):
            cache = {}

        atexit.register(lambda: pickle.dump(cache, open(filename, "w")))

        def new_func(*args):
            if tuple(args) not in cache:
                cache[tuple(args)] = original_func(*args)
            return cache[args]

        return new_func

    return decorator

I tried to use this code as per the example...

@persist_cache_to_disk('users.p')
def get_all_users():
    x = 'some user'
    return x

Update:

This is working at python command prompt, but does not work in ipython notebook.