There are some essential logging techniques that we can use both for debugging as well as operational support of an application. In particular, a good log can help demonstrate that an application meets its security and auditability requirements.

There are times when we'll have multiple logs with different kinds of information. We might separate security, audit, and debugging into separate logs. In some cases, we might want a unified log. We'll look at a few examples of doing this.

Our users may want verbose output to confirm that the program works correctly. This is different from the debugging output; end users are examining how the program solves their problem. They might, for example, want to change their inputs or process your program's outputs differently. Setting the verbosity level produces a log focused on the needs of users.

The warnings module can provide helpful information for developers as well as users. In the case of developers, we...