How to right align level field in Python logging.Formatter
PythonLoggingFormattingPython Problem Overview
I'm currently trying to right align the logging level field in my Python logger so that output such as:
[2011-10-14 13:47:51] [DEBUG] --- starting... (smtphandlers.py:96)
[2011-10-14 13:47:51] [INFO] --- first things first... (smtphandlers.py:97)
[2011-10-14 13:47:51] [WARNING] --- about to end... (smtphandlers.py:98)
[2011-10-14 13:47:51] [DEBUG] --- ending (smtphandlers.py:99)
instead looks like:
[2011-10-14 13:47:51] [ DEBUG] --- starting... (smtphandlers.py:96)
[2011-10-14 13:47:51] [ INFO] --- first things first... (smtphandlers.py:97)
[2011-10-14 13:47:51] [ WARNING] --- about to end... (smtphandlers.py:98)
[2011-10-14 13:47:51] [ DEBUG] --- ending (smtphandlers.py:99)
The format line for the first block is:
logging.Formatter("[%(asctime)s] [%(levelname)s] --- %(message)s (%(filename)s:%(lineno)s)", "%Y-%m-%d %H:%M:%S")
If I know the max level length is 8 (eg: CRITICAL), then I'll right align to 8 spaces. I'm trying to figure out how to achieve this. The following fails because "%(levelname)s" is more than 8 characters (the substitution doesn't happen until later). If I use something like "{0:>20}".format"%(levelname)s", then it works, but that is more padding than I need or want.
logging.Formatter("[%(asctime)s] [" + "{0:>8}".format"%(levelname)s" + "] --- %(message)s (%(filename)s:%(lineno)s)", "%Y-%m-%d %H:%M:%S")
Short of subclassing Formatter, anyone have a way to achieve this?
Python Solutions
Solution 1 - Python
Like this:
logging.Formatter("[%(asctime)s] [%(levelname)8s] --- %(message)s (%(filename)s:%(lineno)s)", "%Y-%m-%d %H:%M:%S")
Solution 2 - Python
Try with this format line :
logging.Formatter("[%(asctime)s] [%(levelname)8s] --- %(message)s (%(filename)s:%(lineno)s)", "%Y-%m-%d %H:%M:%S")
python logger formatter use the standard python string formatting rules