In this chapter, you learned about relational databases and SQL, the language used to work with them. You learned to model and normalize data to reduce the possibility of inconsistencies, and how to convert flat files into relational data. You learned how to work with the psycopg2 library, and went through the arduous task of converting the application to use a SQL backend.
In the next chapter, we'll be reaching out to the cloud. We'll need to contact some remote servers using different networking protocols to exchange data. You'll learn about the Python standard library's modules for working with HTTP and FTP, and use them to download and upload data.
