Technical Note

Python's logging is over-engineered and not quite good enough:

Background

Loggers exist in a tree structure, hierarchy defined by the name. There is a root logger that you cannot change. Loggers have Handlers, Handlers have Formatters. When you call a logging function on a Logger, it searches up the tree for all parent handlers. In simple usage, usually only the root logger has a handler.

Problem

• Changing the format mid-program means finding all the (relevant?) handlers in the tree. pytest for example attaches other handlers so it can capture logging. Our better_config() will set our format on the root logger's handlers.

• You cannot attach two formatters to a handler

• Two handlers cannot access the same file

Having both those be true simultaneously presents problems.

For our process logger, where a lot of context is erronenous, we strip useless data from the process logger by using a filter.