Snippet to setup basic logging in Python.

setup_logging.py

import logging
import os
import sys
import time

LOG_FORMAT = '%(asctime)s %(levelname)-8s %(message)s'
DATE_FORMAT = '%m/%d %H:%M:%S %Z'

# --------------------------------------------------

def cwd_filepath(filename):
    return os.path.join(os.getcwd(), filename)

def setup_basic_logging(log_filepath, log_level=logging.INFO):
    sys.stdout = sys.stderr = open(log_filepath, 'a')

    os.environ['TZ'] = 'US/Pacific'
    time.tzset()

    logging.basicConfig(level=log_level,
                        format=LOG_FORMAT,
                        datefmt=DATE_FORMAT,
                       )

# Example usage:
# setup_basic_logging(cwd_filepath('my_app_log.txt'))

# --------------------------------------------------

class BelowLevelFilter(logging.Filter):
    def __init__(self, level):
        super(BelowLevelFilter, self).__init__()
        self.level = level

    def filter(self, record):
        return record.levelno < self.level

def setup_split_logging(log_level=logging.DEBUG, stderr_level=logging.WARNING):
    """ Makes it log to stdout if level < stderr_level, stderr if level >= stderr_level. """

    os.environ['TZ'] = 'US/Pacific'
    time.tzset()

    logger = logging.getLogger() # The root logger.
    logger.setLevel(log_level)

    formatter = logging.Formatter(fmt=LOG_FORMAT, datefmt=DATE_FORMAT)

    h1 = logging.StreamHandler(sys.stdout)
    h1.setLevel(logging.DEBUG)
    h1.setFormatter(formatter)
    h1.addFilter(BelowLevelFilter(stderr_level))

    h2 = logging.StreamHandler(sys.stderr)
    h2.setLevel(stderr_level)
    h2.setFormatter(formatter)

    logger.addHandler(h1)
    logger.addHandler(h2)