Chapter 9. The Iterator Pattern
We've discussed how many of Python's built-ins and idioms that seem, at first blush, to be non-object-oriented are actually providing access to major objects under the hood. In this chapter, we'll discuss how the for loop that seems so structured is actually a lightweight wrapper around a set of object-oriented principles. We'll also see a variety of extensions to this syntax that automatically create even more types of object. We will cover:
- What design patterns are
- The iterator protocol—one of the most powerful design patterns
- List, set, and dictionary comprehensions
- Generators and coroutines
Design patterns in brief
When engineers and architects decide to build a bridge, or a tower, or a building, they follow certain principles to ensure structural integrity. There are various possible designs for bridges (suspension or cantilever, for example), but if the engineer doesn't use one of the standard designs, and doesn&apos...
