The flyweight pattern

The flyweight pattern is a memory optimization pattern. Novice Python programmers tend to ignore memory optimization, assuming the built-in garbage collector will take care of them. This is usually perfectly acceptable, but when developing larger applications with many related objects, paying attention to memory concerns can have a huge payoff.

The flyweight pattern ensures that objects that share a state can use the same memory for that shared state. It is normally implemented only after a program has demonstrated memory problems. It may make sense to design an optimal configuration from the beginning in some situations, but bear in mind that premature optimization is the most effective way to create a program that is too complicated to maintain.

Let's have a look at the following UML diagram for the flyweight pattern:

Each Flyweight has no specific state. Any time it needs to perform an operation on SpecificState, that state needs to be passed into the Flyweight by the...