Lightweight access with sqlite3

SQLite is a very popular relational database. It's very lightweight and used by many applications, for instance, web browsers such as Mozilla Firefox. Most of the apps in Android use SQLite as a data store.

The sqlite3 module in the standard Python distribution can be used to work with an SQLite database. With sqlite3, we can either store the database in a file or keep it in RAM. For this example, we will do the latter. Import sqlite3 as follows:

import sqlite3

A connection to the database is needed to proceed. If we wanted to store the database in a file, we would provide a filename. Instead, do the following:

with sqlite3.connect(":memory:") as con:

The with statement is standard Python and relies on the presence of a __exit__() method in a special context manager class. With this statement, we don't need to explicitly close the connection. The connection is automatically closed by the context manager. After connecting to a database, we need a cursor, that...