Where is a complete example of logging.config.dictConfig?

Python Problem Overview

I'd like to use dictConfig, but the documentation is a little bit abstract. Where can I find a concrete, copy+paste-able example of the dictionary used with dictConfig?

Python Solutions

Solution 1 - Python

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.

Solution 2 - Python

The accepted answer is nice! But what if one could begin with something less complex? The logging module is very powerful thing and the documentation is kind of a little bit overwhelming especially for novice. But for the beginning you don't need to configure formatters and handlers. You can add it when you figure out what you want.

For example:

import logging.config

DEFAULT_LOGGING = {
    'version': 1,
    'disable_existing_loggers': False,
    'loggers': {
        '': {
            'level': 'INFO',
        },
        'another.module': {
            'level': 'DEBUG',
        },
    }
}

logging.config.dictConfig(DEFAULT_LOGGING)

logging.info('Hello, log')

Solution 3 - Python

Example with Stream Handler, File Handler, Rotating File Handler and SMTP Handler

from logging.config import dictConfig

LOGGING_CONFIG = {
    'version': 1,
    'loggers': {
        '': {  # root logger
            'level': 'NOTSET',
            'handlers': ['debug_console_handler', 'info_rotating_file_handler', 'error_file_handler', 'critical_mail_handler'],
        },
        'my.package': { 
            'level': 'WARNING',
            'propagate': False,
            'handlers': ['info_rotating_file_handler', 'error_file_handler' ],
        },
    },
    'handlers': {
        'debug_console_handler': {
            'level': 'DEBUG',
            'formatter': 'info',
            'class': 'logging.StreamHandler',
            'stream': 'ext://sys.stdout',
        },
        'info_rotating_file_handler': {
            'level': 'INFO',
            'formatter': 'info',
            'class': 'logging.handlers.RotatingFileHandler',
            'filename': 'info.log',
            'mode': 'a',
            'maxBytes': 1048576,
            'backupCount': 10
        },
        'error_file_handler': {
            'level': 'WARNING',
            'formatter': 'error',
            'class': 'logging.FileHandler',
            'filename': 'error.log',
            'mode': 'a',
        },
        'critical_mail_handler': {
            'level': 'CRITICAL',
            'formatter': 'error',
            'class': 'logging.handlers.SMTPHandler',
            'mailhost' : 'localhost',
            'fromaddr': '[email protected]',
            'toaddrs': ['[email protected]', '[email protected]'],
            'subject': 'Critical error with application name'
        }
    },
    'formatters': {
        'info': {
            'format': '%(asctime)s-%(levelname)s-%(name)s::%(module)s|%(lineno)s:: %(message)s'
        },
        'error': {
            'format': '%(asctime)s-%(levelname)s-%(name)s-%(process)d::%(module)s|%(lineno)s:: %(message)s'
        },
    },

}

dictConfig(LOGGING_CONFIG)

Solution 4 - Python

I found Django v1.11.15 default config below, hope it helps

DEFAULT_LOGGING = {
    'version': 1,
    'disable_existing_loggers': False,
    'filters': {
        'require_debug_false': {
            '()': 'django.utils.log.RequireDebugFalse',
        },
        'require_debug_true': {
            '()': 'django.utils.log.RequireDebugTrue',
        },
    },
    'formatters': {
        'django.server': {
            '()': 'django.utils.log.ServerFormatter',
            'format': '[%(server_time)s] %(message)s',
        }
    },
    'handlers': {
        'console': {
            'level': 'INFO',
            'filters': ['require_debug_true'],
            'class': 'logging.StreamHandler',
        },
        'django.server': {
            'level': 'INFO',
            'class': 'logging.StreamHandler',
            'formatter': 'django.server',
        },
        'mail_admins': {
            'level': 'ERROR',
            'filters': ['require_debug_false'],
            'class': 'django.utils.log.AdminEmailHandler'
        }
    },
    'loggers': {
        'django': {
            'handlers': ['console', 'mail_admins'],
            'level': 'INFO',
        },
        'django.server': {
            'handlers': ['django.server'],
            'level': 'INFO',
            'propagate': False,
        },
    }
}

Solution 5 - Python

There's an updated example of declaring a logging.config.dictConfig() dictionary schema buried in the logging cookbook examples. Scroll up from that cookbook link to see a use of dictConfig().

Here's an example use case for logging to both stdout and a "logs" subdirectory using a StreamHandler and RotatingFileHandler with customized format and datefmt.

Imports modules and establish a cross-platform absolute path to the "logs" subdirectory from os.path import abspath, dirname, join import logging from logging.config import dictConfig base_dir = abspath(dirname(file)) logs_target = join(base_dir + "\logs", "python_logs.log")

Establish the schema according to the dictionary schema documentation.

logging_schema = {
    # Always 1. Schema versioning may be added in a future release of logging
    "version": 1,
    # "Name of formatter" : {Formatter Config Dict}
    "formatters": {
        # Formatter Name
        "standard": {
            # class is always "logging.Formatter"
            "class": "logging.Formatter",
            # Optional: logging output format
            "format": "%(asctime)s\t%(levelname)s\t%(filename)s\t%(message)s",
            # Optional: asctime format
            "datefmt": "%d %b %y %H:%M:%S"
        }
    },
    # Handlers use the formatter names declared above
    "handlers": {
        # Name of handler
        "console": {
            # The class of logger. A mixture of logging.config.dictConfig() and
            # logger class-specific keyword arguments (kwargs) are passed in here. 
            "class": "logging.StreamHandler",
            # This is the formatter name declared above
            "formatter": "standard",
            "level": "INFO",
            # The default is stderr
            "stream": "ext://sys.stdout"
        },
        # Same as the StreamHandler example above, but with different
        # handler-specific kwargs.
        "file": {  
            "class": "logging.handlers.RotatingFileHandler",
            "formatter": "standard",
            "level": "INFO",
            "filename": logs_target,
            "mode": "a",
            "encoding": "utf-8",
            "maxBytes": 500000,
            "backupCount": 4
        }
    },
    # Loggers use the handler names declared above
    "loggers" : {
        "__main__": {  # if __name__ == "__main__"
            # Use a list even if one handler is used
            "handlers": ["console", "file"],
            "level": "INFO",
            "propagate": False
        }
    },
    # Just a standalone kwarg for the root logger
    "root" : {
        "level": "INFO",
        "handlers": ["file"]
    }
}

Configure logging with the dictionary schema

dictConfig(logging_schema)

Try some test cases to see if everything is working properly

if __name__ == "__main__":
    logging.info("testing an info log entry")
    logging.warning("testing a warning log entry")

Content Type	Original Author	Original Content on Stackoverflow
Question	David Wolever	View Question on Stackoverflow
Solution 1 - Python	Dave	View Answer on Stackoverflow
Solution 2 - Python	theotheo	View Answer on Stackoverflow
Solution 3 - Python	Yogesh Yadav	View Answer on Stackoverflow
Solution 4 - Python	夜一林风	View Answer on Stackoverflow
Solution 5 - Python	Brent	View Answer on Stackoverflow