Exercises

While writing the examples for this chapter, the authors discovered that it can be very difficult, and extremely educational, to come up with good examples where specific design patterns should be used. Instead of going over current or old projects to see where you can apply these patterns, as we've suggested in previous chapters, think about the patterns and different situations where they might come up. Try to think outside your own experiences. If your current projects are in the banking business, consider how you'd apply these design patterns in a retail or point-of-sale application. If you normally write web applications, think about using design patterns while writing a compiler.

Look at the Decorator pattern and come up with some good examples of when to apply it. Focus on the pattern itself, not the Python syntax we discussed. It's a bit more general than the actual pattern. The special syntax for decorators is, however, something you may want...