Defining web services as functions

We'll look at a RESTful web service, which can "slice and dice" a source of data and provide downloads as JSON, XML, or CSV files. We'll provide an overall WSGI-compatible wrapper but the functions which do the "real work" of the application won't be narrowly constrained to fit the WSGI.

We'll use a simple dataset with four subcollections: the Anscombe Quartet. We looked at ways to read and parse this data in Chapter 3, Functions, Iterators, and Generators". It's a small set of data but it can be used to show the principles of a RESTful web service.

We'll split our application into two tiers: a web tier, which will be a simple WSGI application, and the rest of the processing, which will be more typical functional programming. We'll look at the web tier first so that we can focus on a functional approach to provide meaningful results.

We need to provide two pieces of information to the web service...