Python Module logging Concepts

Internal

• Python Logging

Logging Levels

https://docs.python.org/3/library/logging.html#logging-levels

The logging system can be configured to filter out log messages whose logging level is under a certain threshold. The logging levels, and the corresponding logging functions are, listed from the most important to the least important, are provided below. By default, the logging system is configured to allow log messages of level WARNING and above, INFO and below are discarded.

CRITICAL

Has numeric value 50. Generated with logging.critical().

ERROR

Has numeric value 40. Generated with logging.error().

WARNING

Has numeric value 30. Generated with logging.warning().

WARN seems to be deprecated. warn() is deprecated.

INFO

Has numeric value 20. Generated with logging.info().

DEBUG

Has numeric value 10. Generated with logging.debug().

NOTSET

Has numeric value 0.

Logger

Logger Hierarchy

If the logger name contains dot characters, they separate levels of a hierarchy. Closer to the left, the higher the logger in the logger hierarchy: a has a higher level than a.b . Each level in the hierarchy can be given different properties. At the top of the hierarchy there's a root logger.

The root Logger

At the top of the logger hierarchy, there is a special root logger, called .

Format

The default format, without any customization is <LOGGING_LEVEL>:<logger_name>:<message>.