Expert Python Programming - Third Edition

Basic low-level log practices

The Twelve-Factor App manifesto says that logs should be treated as event streams. So, the log file is not a log by itself, but only an output format. The fact that they are streams means they represent time ordered events. In raw, they are typically in a plaintext format with one line per event, although in some cases they may span across multiple lines (this is typical for any back traces related to runtime errors).

According to the Twelve-Factor App methodology, the application should never be aware of the format in which logs are stored. This means that writing to the file, or log rotation and retention should never be maintained by the application code.

These are the responsibilities of the environment in ...