Question

How do I use dictConfig? How should I specify its input config dictionary?

Answer 1

How about here! The corresponding documentation reference is configuration-dictionary-schema.

LOGGING_CONFIG = { 
    'version': 1,
    'disable_existing_loggers': True,
    'formatters': { 
        'standard': { 
            'format': '%(asctime)s [%(levelname)s] %(name)s: %(message)s'
        },
    },
    'handlers': { 
        'default': { 
            'level': 'INFO',
            'formatter': 'standard',
            'class': 'logging.StreamHandler',
            'stream': 'ext://sys.stdout',  # Default is stderr
        },
    },
    'loggers': { 
        '': {  # root logger
            'handlers': ['default'],
            'level': 'WARNING',
            'propagate': False
        },
        'my.packg': { 
            'handlers': ['default'],
            'level': 'INFO',
            'propagate': False
        },
        '__main__': {  # if __name__ == '__main__'
            'handlers': ['default'],
            'level': 'DEBUG',
            'propagate': False
        },
    } 
}

Usage:

import logging.config

# Run once at startup:
logging.config.dictConfig(LOGGING_CONFIG)

# Include in each module:
log = logging.getLogger(__name__)
log.debug("Logging is configured.")

In case you see too many logs from third-party packages, be sure to run this config using logging.config.dictConfig(LOGGING_CONFIG) before the third-party packages are imported.

To add additional custom info to each log message using a logging filter, consider this answer.