Python logging dictConfig

.py

# https://docs.python.org/2/library/logging.config.html
# https://docs.python.org/3.6/library/logging.config.html

import logging
import logging.config
import datetime

DEFAULT_LOGGING = {
    'version': 1,
    'disable_existing_loggers': False,
    'formatters': { 
        'standard': { 
            'format': '%(asctime)s - %(message)s'
        },
        'complete': {
            'format': '%(asctime)s - PID: %(process)d - PNAME: %(processName)s' \
                      ' - TID: %(thread)d - TNAME: %(threadName)s' \
                      ' - %(levelname)s - %(filename)s - %(message)s',
        },
    },
    'handlers': { 
        'default': { 
            'level': 'INFO',
            'formatter': 'standard',
            'class': 'logging.StreamHandler',
        },
        'file': { 
            'level': 'INFO',
            'formatter': 'standard',
            'class': 'logging.FileHandler',
            'filename': datetime.datetime.now().strftime('%Y%m%d.log'),
        },
        'rewrite': { 
            'level': 'INFO',
            'formatter': 'complete',
            'class': 'logging.FileHandler',
            'filename': datetime.datetime.now().strftime('%Y%m%d2.log'),
            'mode': 'w',
        },
    },
    'loggers': {
        '': {
            'handlers': ['default', 'file', 'rewrite'],
            'level': 'INFO',
            'propagate': True
        },
        'another.module': {
            'level': 'DEBUG',
        },
    }
}

logging.config.dictConfig(DEFAULT_LOGGING)
logging.info('Hello, log')


# def setup_logger():
#     """
#     Initializes and setups 2 logger handlers: console (INFO) and file (DEBUG).
#     """
#     logger = logging.getLogger(__name__)
#     logger.setLevel(logging.DEBUG)

#     formatter = logging.Formatter('%(asctime)s - PID: %(process)d - PNAME: %(processName)s' \
#                                   ' - TID: %(thread)d - TNAME: %(threadName)s' \
#                                   ' - %(levelname)s - %(filename)s - %(message)s')

#     ch = logging.StreamHandler()
#     ch.setFormatter(formatter)
#     ch.setLevel(logging.INFO)
#     logger.addHandler(ch)

#     filename = datetime.datetime.now().strftime('%Y%m%d.log')
#     fh = logging.FileHandler(filename, mode='w')
#     fh.setFormatter(formatter)
#     fh.setLevel(logging.DEBUG)
#     logger.addHandler(fh)

#     return logger

# logger = setup_logger()

Hi!
I want to ask why in line 42 the key is an empty string.
I have read the doc and I think it must be a logger's name, but it still works when I call logger = logging.getLogger('') or logger = logging.getLogger("some_name").
But if I set the name in the key, it will not work.
I don't know why.
After all, thanks for your nice work!

For what I remember, the empty str is the way to define the default logger.