On 11/15/2011 8:57 AM, Christopher Armstrong wrote:

If you pass a 'system' kwarg to log.msg then it will go in that field.

log.msg("hi", system="stuff") results in <date> [stuff] hi

This triggered me to look further into what LogPublisher.msg does, since I've long wanted to customize the format of the output. I found what I wanted in http://twistedmatrix.com/documents/current/api/twisted.python.log.ILogObserver.html :

In msg(), the message gets added to the kwargs dictionary (along with a timestamp called 'time'), and that dict is passed to LogObserver.emit, which uses textFromEventDict() to create what's actually output. This dictionary has the following keys recognized by textFromEventDict:

message: A tuple of str containing messages to be logged.
system: A str which indicates the "system" which is generating this event.
isError: A bool indicating whether this event represents an error.
failure: A failure.Failure instance, required if the event is an error.
why: Used as header of the traceback in case of errors.
format: A string format used in place of message to customize the event. The intent is for the observer to format a message by doing something like format % eventDict.

So, for example, you could do log.msg(format='....', foo='stuff', bar='things')

I suggest that this be added to the documentation string of the msg() method and http://twistedmatrix.com/documents/current/core/howto/logging.html.

Don Dwiggins
Advanced Publishing Technology