Chapter 12. Python Design Patterns II
In this chapter we will be introduced to several more design patterns. Once again, we'll cover the canonical examples as well as any common alternative implementations in Python. We'll be discussing:
- The adapter pattern
- The facade pattern
- Lazy initialization and the flyweight pattern
- The command pattern
- The abstract factory pattern
- The composition pattern
The adapter pattern
Unlike most of the patterns we reviewed in Chapter 8, Strings and Serialization, the adapter pattern is designed to interact with existing code. We would not design a brand new set of objects that implement the adapter pattern. Adapters are used to allow two pre-existing objects to work together, even if their interfaces are not compatible. Like the display adapters that allow VGA projectors to be plugged into HDMI ports, an adapter object sits between two different interfaces, translating between them on the fly. The adapter object's sole purpose is to perform...
