Testing named vs. unnamed loggers

bash_output

$ python named_logger.py
WARNING:root:warning
ERROR:root:error
CRITICAL:root:critical
Hi.
$ python unnamed_logger.py
2017-11-28 08:05:40  INFO: Writing verbose debug log to: /var/folders/th/3tqg05g54f73x0k_mstm5wy1_0g_xw/T/mm.XcXk7B.log
2017-11-28 08:05:40  INFO: info
2017-11-28 08:05:40  WARNING: warning
2017-11-28 08:05:40  ERROR: error
2017-11-28 08:05:40  CRITICAL: critical
Hi.
2017-11-28 08:05:40  INFO: Stuff

named_logger.py

#!/usr/bin/python

from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
from __future__ import unicode_literals

import logging
import sys
from tempfile import NamedTemporaryFile


def setup_logging(log_fname_prefix, loglevel):
    """
    Set up logging for common usage.

    This logger prints out stream content to sys.stdout formatted like this:
        2017-11-27 20:23:13  INFO: Message
    If the level is set to anything less than ERROR, a debug log file is also
    created, and all content (logging.DEBUG and up) is sent there as well.

    Args:
        log_fname_prefix (str): prefix for temp file name for debug log.
        loglevel (int): default level for output. Anything below this level is
            not shown. A value below ERROR creates a debug log file.
    """
    mylogger = logging.getLogger(log_fname_prefix)
    mylogger.setLevel(logging.DEBUG)
    stream_handler = logging.StreamHandler(sys.stdout)  # defaults to stderr
    stream_handler.setLevel(loglevel)
    stream_handler.setFormatter(logging.Formatter(
        fmt='%(asctime)s  %(levelname)s: %(message)s', datefmt='%Y-%m-%d %H:%M:%S'))
    mylogger.addHandler(stream_handler)

    if loglevel < logging.ERROR:
        log_file = NamedTemporaryFile(prefix=log_fname_prefix + '.',
                                      suffix='.log', delete=False)
        file_handler = logging.FileHandler(log_file.name)
        file_handler.setLevel(logging.DEBUG)
        file_handler.setFormatter(logging.Formatter(
            fmt='%(asctime)s  %(message)s', datefmt='%Y-%m-%d %H:%M:%S'))
        mylogger.addHandler(file_handler)
        logging.info("Writing verbose debug log to: " + log_file.name)
    return mylogger


logger = setup_logging(
    'mm',
    logging.INFO
)

logging.debug("debug")
logging.info("info")
logging.warning("warning")
logging.error("error")
logging.critical("critical")

print('Hi.')

logging.info("Stuff")

unnamed_logger.py

#!/usr/bin/python

from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
from __future__ import unicode_literals

import logging
import sys
from tempfile import NamedTemporaryFile


def setup_logging(log_fname_prefix, loglevel):
    """
    Set up logging for common usage.

    This logger prints out stream content to sys.stdout formatted like this:
        2017-11-27 20:23:13  INFO: Message
    If the level is set to anything less than ERROR, a debug log file is also
    created, and all content (logging.DEBUG and up) is sent there as well.

    Args:
        log_fname_prefix (str): prefix for temp file name for debug log.
        loglevel (int): default level for output. Anything below this level is
            not shown. A value below ERROR creates a debug log file.
    """
    mylogger = logging.getLogger()
    mylogger.setLevel(logging.DEBUG)
    stream_handler = logging.StreamHandler(sys.stdout)  # defaults to stderr
    stream_handler.setLevel(loglevel)
    stream_handler.setFormatter(logging.Formatter(
        fmt='%(asctime)s  %(levelname)s: %(message)s', datefmt='%Y-%m-%d %H:%M:%S'))
    mylogger.addHandler(stream_handler)

    if loglevel < logging.ERROR:
        log_file = NamedTemporaryFile(prefix=log_fname_prefix + '.',
                                      suffix='.log', delete=False)
        file_handler = logging.FileHandler(log_file.name)
        file_handler.setLevel(logging.DEBUG)
        file_handler.setFormatter(logging.Formatter(
            fmt='%(asctime)s  %(message)s', datefmt='%Y-%m-%d %H:%M:%S'))
        mylogger.addHandler(file_handler)
        logging.info("Writing verbose debug log to: " + log_file.name)
    return mylogger


logger = setup_logging(
    'mm',
    logging.INFO
)

logging.debug("debug")
logging.info("info")
logging.warning("warning")
logging.error("error")
logging.critical("critical")

print('Hi.')

logging.info("Stuff")