SaltyCrane Blog — Notes on JavaScript and web development

Notes on Python logging

Date:  |  Modified:  |  Tags: python  |  3 Comments

mylogging.py:

import logging
import sys

DEBUG_LOG_FILENAME = '/var/log/my-debug.log'
WARNING_LOG_FILENAME = '/var/log/my-warning.log'

# set up formatting
formatter = logging.Formatter('[%(asctime)s] %(levelno)s (%(process)d) %(module)s: %(message)s')

# set up logging to STDOUT for all levels DEBUG and higher
sh = logging.StreamHandler(sys.stdout)
sh.setLevel(logging.DEBUG)
sh.setFormatter(formatter)

# set up logging to a file for all levels DEBUG and higher
fh = logging.FileHandler(DEBUG_LOG_FILENAME)
fh.setLevel(logging.DEBUG)
fh.setFormatter(formatter)

# set up logging to a file for all levels WARNING and higher
fh2 = logging.FileHandler(WARNING_LOG_FILENAME)
fh2.setLevel(logging.WARN)
fh2.setFormatter(formatter)

# create Logger object
mylogger = logging.getLogger('MyLogger')
mylogger.setLevel(logging.DEBUG)
mylogger.addHandler(sh)
mylogger.addHandler(fh)
mylogger.addHandler(fh2)

# create shortcut functions
debug = mylogger.debug
info = mylogger.info
warning = mylogger.warning
error = mylogger.error
critical = mylogger.critical

testlogging.py:

from mylogging import debug, info, warning, error

debug('debug message')
info('info message')
warning('warning message')
error('error message')

Run it:

python testlogging.py

Console output:

[2009-10-07 12:45:59,713] 10 (22886) testlogging: debug message
[2009-10-07 12:45:59,718] 20 (22886) testlogging: info message
[2009-10-07 12:45:59,718] 30 (22886) testlogging: warning message
[2009-10-07 12:45:59,719] 40 (22886) testlogging: error message

cat debug.log:

[2009-10-07 12:45:59,713] 10 (22886) testlogging: debug message
[2009-10-07 12:45:59,718] 20 (22886) testlogging: info message
[2009-10-07 12:45:59,718] 30 (22886) testlogging: warning message
[2009-10-07 12:45:59,719] 40 (22886) testlogging: error message

cat warning.log:

[2009-10-07 12:45:59,718] 30 (22886) testlogging: warning message
[2009-10-07 12:45:59,719] 40 (22886) testlogging: error message

Note: if you get a permission denied error for the log file, you can do this:

sudo touch /var/log/my-debug.log
sudo touch /var/log/my-warning.log
sudo chmod 666 /var/log/my-debug.log
sudo chmod 666 /var/log/my-warning.log

Documentation

Comments


#1 Jabba Laci commented on :

Thanks, this is just what I need. I wanted a solution that prints to stdout AND writes the same thing to a file.


#2 bjd2385 commented on :

Thanks! This is cool. I'm not new to Python, but I recently became interested in logging the output of files like this.

disqus:2653152257


#3 FrostyX commented on :

Nice setup, thanks

disqus:3500700800