structlog 22.2.0

Structured Logging for Python

structlog is the production-ready logging solution for Python:

• Simple: At its core, everything is about functions that take and return dictionaries – all hidden behind familiar APIs.
• Powerful: Functions and dictionaries aren’t just simple, they’re also powerful. structlog leaves you in control.
• Fast: structlog is not hamstrung by designs of yore. Its flexibility comes not at the price of performance.

Thanks to its flexible design, you choose whether you want structlog to take care of the output of your log entries or whether you prefer to forward them to an existing logging system like the standard library's logging module.

The output format is just as flexible and structlog comes with support for JSON, logfmt, as well as pretty console output out-of-the-box:

Sponsors

structlog would not be possible without our amazing sponsors. Especially those generously supporting us at the The Organization tier and higher:

Please consider joining them to help make structlog’s maintenance more sustainable!

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structlog has been successfully used in production at every scale since 2013, while embracing cutting-edge technologies like asyncio, context variables, or type hints as they emerged. Its paradigms proved influential enough to help design structured logging packages across ecosystems.

Project Information

• License: dual Apache License, version 2 and MIT
• Get Help: please use the structlog tag on Stack Overflow
• Supported Python Versions: 3.7 and later
• PyPI
• Source Code
• Documentation
• Changelog
• Third-party Extensions

structlog for Enterprise

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Release Information

Deprecated

• Accessing package metadata as attributes on the structlog module is deprecated (e.g. structlog.__version__). Please use importlib.metadata instead (for Python 3.7: the importlib-metadata PyPI package).
• The structlog.types module is now deprecated in favor of the structlog.typing module. It seems like the Python typing community is settling on this name.

Added

• FilteringBoundLogger (used by default) now allows for string interpolation using positional arguments:

  >>> log.info("Hello %s! The answer is %d.", "World", 42, x=1)
  2022-10-07 10:04.31 [info     ] Hello World! The answer is 42. x=1
  

  #454

• FilteringBoundLogger now also has support for asyncio-based logging. Instead of a wrapper class like structlog.stdlib.AsyncBoundLogger, async equivalents have been added for all logging methods. So instead of log.info("hello") you can also write await log.ainfo("hello") in async functions and methods.

  This seems like the better approach and if it's liked by the community, structlog.stdlib.BoundLogger will get those methods too. #457

Changed

• The documentation has been heavily overhauled. Have a look if you haven't lately! Especially the graphs in the standard library chapter have proven valuable to many.
• The build backend has been switched to Hatch.

Fixed

• The timestamps in the default configuration now use the correct separator (:) for seconds.

Credits

structlog is written and maintained by Hynek Schlawack. The idea of bound loggers is inspired by previous work by Jean-Paul Calderone and David Reid.

The development is kindly supported by my employer Variomedia AG, structlog’s Tidelift subscribers, and all my amazing GitHub Sponsors.

A full list of contributors can be found in GitHub’s overview.

The logs-loving futuristic beaver logo has been contributed by Russell Keith-Magee.