Another way of debugging a misbehaving application is to inspect its log files. Log files are special files in which an application writes down all sorts of things, normally related to what's going on inside of it. If an important procedure is started, I would typically expect a corresponding line in the logs. It is the same when it finishes, and possibly for what happens inside of it.
Errors need to be logged so that when a problem happens, we can inspect what went wrong by taking a look at the information in the log files.
There are many different ways to set up a logger in Python. Logging is very malleable and you can configure it. In a nutshell, there are normally four players in the game: loggers, handlers, filters, ...
