Coloredlogs: Colored Terminal Output for Python's Logging Module

Warnings

• breaking In version 15.0, `coloredlogs` stopped enabling system logging by default on macOS and Windows due to problematic behavior. This is a backwards incompatible change.
  Fix: If you previously relied on automatic system logging on these platforms, you may need to explicitly configure it or adjust your logging setup.
• breaking Starting with version 14.0, `coloredlogs` dropped `colorama` as a *required* dependency for Windows 10 users, integrating native ANSI support instead. While `colorama` will still be used if installed, its implicit presence or absence can cause issues if not considered, especially for older Windows versions or specific environments.
  Fix: For Windows installations prior to version 10.0.14393 or if native ANSI support is not working as expected, explicitly install `colorama`: `pip install colorama`.
• gotcha `coloredlogs.install()`, when called without a specific `logger` argument, applies its configuration to the *root logger*. This can unintentionally change the effective logging level for *all* loggers in your application, including those from third-party libraries, potentially silencing or making logs unexpectedly verbose. The default log level for the root logger is `INFO` when using `coloredlogs`, which differs from Python's default `WARNING`.
  Fix: Always pass a specific logger instance to `coloredlogs.install(logger=my_logger)` if you only want to affect that logger. If you intend to modify the root logger, be aware of the default `INFO` level and explicitly set `logging.getLogger().setLevel(logging.WARNING)` if Python's default `WARNING` level is desired for other parts of your application after `coloredlogs.install()` has run.
• breaking In release 6.0, `coloredlogs.install()` changed its default root logger level handling and `enable_system_logging()`'s default logging level changed from `DEBUG` to `INFO`. This affected the verbosity of logs for users migrating from older versions.
  Fix: If migrating from versions older than 6.0, explicitly set `level='DEBUG'` in `coloredlogs.install()` or `coloredlogs.install(syslog='debug')` if `DEBUG` verbosity is desired.
• gotcha When `coloredlogs` is active, and logging output is redirected to a file, the file will contain plain text without ANSI escape sequences (colors) by default, because `coloredlogs` detects it's not attached to an interactive terminal. This is by design, but can be a 'gotcha' if users expect colored log files for later viewing.
  Fix: This is intended behavior. If colored output in files is desired (e.g., for viewing in Vim with specific plugins or converting to HTML), specific tools or configurations are needed, such as `coloredlogs --to-html your-command` for HTML output.

Install

• pip install coloredlogs Standard Installation
• pip install 'coloredlogs[cron]' Installation with Cron features

Imports

• coloredlogs

  import coloredlogs, logging

  The primary interaction is through module-level functions like `coloredlogs.install()`.
• ColoredFormatter

  from coloredlogs import ColoredFormatter

  While `ColoredFormatter` can be imported and used directly, `coloredlogs.install()` is the recommended and simpler way to integrate colored logging as it handles handler setup.

Quickstart

This quickstart demonstrates how to import `coloredlogs` and the standard `logging` module, create a logger, and then apply colored output using `coloredlogs.install()` to a specific logger with a 'DEBUG' level. Log messages at different severity levels will then be displayed with corresponding colors in the terminal.

import coloredlogs, logging

# Create a logger object. By default, coloredlogs.install()
# will apply to the root logger if no logger is specified.
logger = logging.getLogger(__name__)

# Install coloredlogs on the logger.
# You can also pass level='INFO' or other levels.
coloredlogs.install(level='DEBUG', logger=logger)

# Some examples of log messages.
logger.debug('This is a debug message')
logger.info('This is an info message')
logger.warning('This is a warning message')
logger.error('This is an error message')
logger.critical('This is a critical message')