Using signals, I try to track the difference between the old instance of an object and the new instance when the Model is saved.

I tried this :

But logically in the model_post_init_handler method, it’s a reference of the object that is stored in __original_instance. So, instance.__original_instance.is_used and instance.is_used will always be the same.

How could I store a “snapshot” of the object when he is initiated, so that I will be able to track what is edited ?