This does not appear to be really useful for pyiso8601, but adds noise to all project using this. I had to disable debug logging on pyiso8601 on three projects of mine, and there are at least two public bugs about this:
I'm slightly on the fence about this one. Strictly speaking the log4j pattern encourages libraries to aggressively use the DEBUG level and defer policy decisions to the consumer of the library, in practice there's a sort of "logging level" creep where a lot of projects wind up logging to DEBUG, which makes the pattern here annoying.
As a bonus even with the deferred formatting pattern there's a performance impact too.
I think on balance the logging doesn't add much and leads to problems for some consuming projects, so I'm going to merge this change.