Serializing objects

Nowadays, we take the ability to write data to a file and retrieve it at an arbitrary later date for granted. As convenient as this is (imagine the state of computing if we couldn't store anything!), we often find ourselves converting data we have stored in a nice object or design pattern in memory into some kind of clunky text or binary format for storage, transfer over the network, or remote invocation on a distant server.

The Python pickle module is an object-oriented way to store objects directly in a special storage format. It essentially converts an object (and all the objects it holds as attributes) into a sequence of bytes that can be stored or transported however we see fit.

For basic work, the pickle module has an extremely simple interface. It is comprised of four basic functions for storing and loading data; two for manipulating file-like objects, and two for manipulating bytes objects (the latter are just shortcuts to the file-like interface, so we don't have...