Understanding persistence, class, state, and representation
Primarily, our Python objects exist in volatile computer memory. They can only live as long as the Python process is running. They may not even live that long; they may only live as long as they have references in a namespace. If we want an object that outlives the Python process or namespace, we need to make it persistent.
Most operating systems offer persistent storage in the form of a filesystem. This usually includes disk drives, flash drives, or other forms of non-volatile storage. It seems like it's simply a matter of transferring bytes from the memory to a disk file.
The complexity arises because our in-memory Python objects have references to other objects. An object refers to its class. The class refers to its metaclass and any base classes. The object might be a container and refer to other objects. The in-memory version of an object is a web of references and relationships. As the memory locations are not fixed, the relationships...
