How to Properly Format the Python Logging Formatter?
I Try to Format the Way My Python Logging Formatter Outputs Strings. I Wrote a Minimalistic Example to Show the Problem: Import Logging from Pathlib Import...
I try to format the way my Python logging formatter outputs strings. I wrote a minimalistic example to show the problem:
import logging
from pathlib import Path
# create auxiliary variables
loggerName = Path(__file__).stem
# create logging formatter
logFormatter = logging.Formatter(fmt=' %(name)s :: %(levelname)s :: %(message)s')
# create logger
logger = logging.getLogger(loggerName)
logger.setLevel(logging.DEBUG)
# create console handler
consoleHandler = logging.StreamHandler()
consoleHandler.setLevel(logging.WARNING)
consoleHandler.setFormatter(logFormatter)
# Add console handler to logger
logger.addHandler(consoleHandler)
# Test
logger.debug('debug message')
logger.info('info message')
logger.warning('warn message')
logger.error('error message')
logger.critical('critical message')
The script will give a an output without proper formatting:
logger :: WARNING :: warn message
logger :: ERROR :: error message
logger :: CRITICAL :: critical message
I would like to change the formatting to keep left side of my logging in order:
logger :: WARNING :: warn message
logger :: ERROR :: error message
logger :: CRITICAL :: critical message
1 Answer
The format string uses Python's regular %-formatting, also called printf-style formatting. You can read more about it in the docs at What you're looking for is a minimum field width paired with the - flag:
'-'The converted value is left adjusted
So, with
logFormatter = logging.Formatter(fmt=' %(name)s :: %(levelname)-8s :: %(message)s')
you will get the following output:
test :: WARNING :: warn message
test :: ERROR :: error message
test :: CRITICAL :: critical message
Elena Rostova holds a Master's degree in Public Health Journalism. She covers groundbreaking medical research, holistic wellness trends, mental health awareness, and nutritional science.
