Appendix A. Data Structures

This appendix describes some structures used in several recipes through the book.

There are two objectives in describing them here (besides keeping the explanation in a single place): one is that you understand the structure of the data being used. The second, is allowing you to create your own data in the format of your choice: database, Excel file, and so on, excepting of course, when the data is used in a recipe that explain database steps, in which case the data should be in a database.