structlog: Structured Logging for Python

Simple. Powerful. Fast. Pick three.

structlog is the production-ready logging solution for Python:

• Simple: Everything is about functions that take and return dictionaries – all hidden behind familiar APIs.
• Powerful: Functions and dictionaries aren’t just simple but 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!

Introduction

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.

A short explanation on why structured logging is good for you, and why structlog is the right tool for the job can be found in the Why chapter of our documentation.

Once you feel inspired to try it out, check out our friendly Getting Started tutorial.

For a fully-fledged zero-to-hero tutorial, check out A Comprehensive Guide to Python Logging with structlog.

If you prefer videos over reading, check out Markus Holtermann's talk Logging Rethought 2: The Actions of Frank Taylor Jr.:

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.

The logs-loving beaver logo has been contributed by Lynn Root.

Project Links

• Get Help (use the structlog tag on Stack Overflow)
• PyPI
• GitHub
• Documentation
• Changelog
• Third-party Extensions

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