This part of the book showed how Python can easily build extensible applications that capture the essence of a business problem and leave users free to build their own solutions around the core.
As an example, we built a small class library which, while quick and dirty, is applicable to a wide range of financial problems. We hope that this has demonstrated the ease with which Python can capture abstractions and manipulate data.
We don’t yet have an application program to use these classes or a way to look at the data. Over the next few chapters, we will build one around this class library.