[Python-ideas] Alternative formatting styles for logging events in Python 3.3

[Nick Coghlan]

Via the new "style" parameter to logging.Formatter objects, Python 3.2
adds support for newer formatting styles (str.format, string.template)
when defining output formats for log messages. However, actual logging
calls are still constrained to using %-formatting if they want to
benefit from the "lazy formatting" feature (you can obviously generate
pre-formatted messages any way you like).

For 3.3, I'd like to propose extending this flexibility to the input
side as well:

1. Add an optional style parameter to logging.Logger and
logging.getLogger. This would then become the "default style" for any
messages logged using that logger. In the case of getLogger, if the
logger already exists and the styles don't match, raise an exception.

2. Add an optional style parameter to the Logger event recording
methods (debug(), info(), et al) and the module level convenience
functions. If supplied, this would override the default choice
configured in the logger for that particular message.

By default, all loggers (including the root logger) would continue to
expect %-formatting. However, applications and libraries would be free
to use the alternative formatting for their own logging without
affecting other loggers.

Thoughts?

Cheers,
Nick.

-- 
Nick Coghlan   |   ncoghlan at gmail.com   |   Brisbane, Australia