Since Python tuples are immutable objects, they're another excellent example of objects suitable for functional programming. A Python tuple has very few method functions, so almost everything is done through functions using prefix syntax. There are a number of use cases for tuples, particularly when working with list-of-tuple, tuple-of-tuple and generator-of-tuple constructs.

Of course, namedtuples add an essential feature to a tuple: a name that we can use instead of an index. We can exploit namedtuples to create objects that are accretions of data. This allows us to write pure functions based on stateless objects, yet keep data bound into tidy object-like packages.

We'll almost always use tuples (and namedtuples) in the context of a collection of values. If we're working with single values, or a tidy group of exactly two values, we'll usually use named parameters to a function. When working with collections, however, we might need to have iterable-of-tuples or...