Learn how Python's dictionary data structure ... which can be any Python object. You use a key to obtain its related values, and the lookup time for each key/value pair is highly constant.

This dictionary ... with index-name key pair allowing to iterate over items using either: names or indexes. It can be useful for many many other similar use-cases, and there is no limit to the number ...

It's just meant to give a rough idea. It writes every time you set a value, but only the key/value pair. So the cost of adding an item stays constant. On the other hand, lots of updates / deletes / re ...