[Python-Dev] transitioning from % to {} formatting

Antoine Pitrou solipsis at pitrou.net
Wed Sep 30 19:01:35 CEST 2009

James Y Knight <foom <at> fuhm.net> writes:
> The user could write either:
> logging.Formatter("%(asctime)s - %(name)s - %(level)s - %(msg)s")
> (as always -- that can't be changed without a long deprecation  
> period), or:
> logging.Formatter(newstyle_formatstr("{asctime} - {name} - {level} -  
> {msg}")

Why not allow logging.Formatter to take a callable, which would in turn call the
callable with keyword arguments?

Therefore, you could write:
   logging.Formatter("{asctime} - {name} - {level} - {msg}".format)

and then:
   logging.critical(name="Python", msg="Buildbots are down")

All this without having to learn about a separate "compatibility wrapper object".



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