How to break information on an event for the logging

Question

I have been using the logging module in Python for a while. My doubt is not so much a technical one, but that I am not sure of the best practices with the messages. The issue is that sometimes an event happens and I want to dump information about it in the log, but a lot of information. I can build a single long string, and use it in an log.info() command. That is alright, except for the fact that the result is hardly human-readable. Introducing the character '\n' in the string indeed breaks the message into separate lines in the log file, but left-justified, it looks ugly because in the beginning of the logging formatter I am writing the date/time, user, etc.

On the other hand I can split the message into different calls to log.info(), but that makes it look as if they were different events.

EDIT: Additional information.

If I do different log calls, it looks like

2012-10-01 11:55:00,674 - SQLBOLPVWBA01 - WARNING   | ---------- Warning 001: a test was not passed ----------
2012-10-01 11:55:00,694 - SQLBOLPVWBA01 - WARNING   | File: \\b1snnasries01.SAN.CORP\D_8525_50_01\ValidacionModelos\Usuarios\Equity\testsValidationLibrary\XMLs\barrierMC\barrierMCbasket_0002_Q011388.xml
2012-10-01 11:55:00,704 - SQLBOLPVWBA01 - WARNING   | Parametrization: configMatlabMC8192.m
2012-10-01 11:55:00,732 - SQLBOLPVWBA01 - WARNING   | Expected: {'premium': 0.1302634916172996, 'stdErr': 0.0016369990559715}
2012-10-01 11:55:00,765 - SQLBOLPVWBA01 - WARNING   | Calculated: {'premium': 0.13526349161729959, 'stdErr': 0.0016369990559715229}

What is the usual/best practice here?

I think I would like something like

2012-10-01 11:55:00,674 - SQLBOLPVWBA01 - WARNING  | ---------- Warning 001: a test was not passed ----------
                                                   | File: \\b1snnasries01.SAN.CORP\D_8525_50_01\ValidacionModelos\Usuarios\Equity\testsValidationLibrary\XMLs\barrierMC\barrierMCbasket_0002_Q011388.xml
                                                   | Parametrization: configMatlabMC8192.m
                                                   | Expected: {'premium': 0.1302634916172996, 'stdErr': 0.0016369990559715}
                                                   | Calculated: {'premium': 0.13526349161729959, 'stdErr': 0.0016369990559715229}

Answer 1

Log the messages using \n to separate the lines, as you've already considered, then write a custom Formatter subclass which splits the message into separate lines, inserts the appropriate whitespace prefix for the subsequent lines and joins them back together again.