Help & Guides

• Switching from Standard Logging to Loguru
  • Introduction to logging in Python
  • Fundamental differences between logging and loguru
  • Replacing getLogger() function
  • Replacing Logger objects
  • Replacing Handler, Filter and Formatter objects
  • Replacing LogRecord objects
  • Replacing % style formatting of messages
  • Replacing exc_info argument
  • Replacing extra argument and LoggerAdapter objects
  • Replacing isEnabledFor() method
  • Replacing addLevelName() and getLevelName() functions
  • Replacing basicConfig() and dictConfig() functions
  • Replacing captureWarnings() function
  • Replacing assertLogs() method from unittest library
  • Replacing caplog fixture from pytest library
• Frequently Asked Questions and Troubleshooting Tips for Loguru
  • How do I create and configure a logger?
  • Why are my logs duplicated in the output?
  • How do I set the logging level?
  • How do I customize the log format and re-use the default one?
  • Why are my logs not colored?
  • Why are my logs not appearing in the output?
  • How can I use different loggers in different modules of my application?
  • Why are my log files sometimes duplicated or the content trimmed?
  • Why logging a message with f-string sometimes raises an exception?
  • How do I fix “ValueError: I/O operation error on closed file”?
  • How do I prevent “RuntimeError” due to “deadlock avoided”?
  • Why is the source (name, file, function, line) of the log message incorrect or missing?
  • Why can’t I access the Logger class and other types at runtime?
• Code Snippets and Recipes for Loguru
  • Security considerations when using Loguru
  • Avoiding logs to be printed twice on the terminal
  • Changing the level of an existing handler
  • Configuring Loguru to be used by a library or an application
  • Sending and receiving log messages across network or processes
  • Resolving UnicodeEncodeError and other encoding issues
  • Logging entry and exit of functions with a decorator
  • Using logging function based on custom added levels
  • Setting permissions on created log files
  • Preserving an opt() parameter for the whole module
  • Serializing log messages using a custom function
  • Rotating log file based on both size and time
  • Adapting colors and format of logged messages dynamically
  • Dynamically formatting messages to properly align values with padding
  • Customizing the formatting of exceptions
  • Displaying a stacktrace without using the error context
  • Manipulating newline terminator to write multiple logs on the same line
  • Capturing standard stdout, stderr and warnings
  • Circumventing modules whose __name__ value is absent
  • Interoperability with tqdm iterations
  • Using Loguru’s logger within a Cython module
  • Creating independent loggers with separate set of handlers
  • Compatibility with multiprocessing using enqueue argument
  • Testing logging