Appendix A. Data Structures

This appendix describes some structures used in several recipes throughout 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, except of course when the data is used in a recipe that explains database steps, in which case the data should be in a database.