[Python-Dev] Using logging in the stdlib and its unit tests (original) (raw)

Antoine Pitrou solipsis at pitrou.net
Tue Dec 7 21:50:53 CET 2010

On Tue, 7 Dec 2010 20:26:06 +0000 (UTC) Vinay Sajip <vinay_sajip at yahoo.co.uk> wrote:

>From my perspective and as mentioned in the logging documentation, library code which uses logging should add a NullHandler instance to any top-level logger, which will avoid any "No handlers could be found for logger XXX" message if no logging handlers have been set up. This applies to stdlib code, too, though it would be good if a logger namespace could be agreed for stdlib usage. (The logging package itself uses the logger "py.warnings" to redirect warnings to logging when configured to do so. Perhaps we could standardize on "py.XXX" for stdlib usage?)

I thought "error" and "critical" messages were logged to stderr by default? Isn't it the case?

If any library defining a logger must also add a NullHandler just in case, ISTM that complicates a lot the use of logging (and could explain its impopularity). Both for library writers and application writers, apparently (since the former will have to add the NullHandler, and the latter will have to override it so that error messages get printed out rather than lost).

Regards

Antoine.

More information about the Python-Dev mailing list