structlog 25.5.0
Structured Logging for Python
Requires Python: >=3.8
Keywords: log, logging, structure, structured

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    <img
        src="https://www.structlog.org/en/stable/_static/structlog_logo_small.png"
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*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*](https://brandur.org/logfmt), as well as pretty console output out-of-the-box:

[![Screenshot of colorful structlog output with ConsoleRenderer](https://github.com/hynek/structlog/blob/main/docs/_static/console_renderer.png?raw=true)](https://github.com/hynek/structlog/blob/main/docs/_static/console_renderer.png?raw=true)


## Sponsors

*structlog* would not be possible without our [amazing sponsors](https://github.com/sponsors/hynek).
Especially those generously supporting us at the *The Organization* tier and higher:

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import pathlib, tomllib

for sponsor in tomllib.loads(pathlib.Path("pyproject.toml").read_text())["tool"]["sponcon"]["sponsors"]:
      print(f'<a href="{sponsor["url"]}"><img title="{sponsor["title"]}" src="https://www.structlog.org/en/25.5.0/_static/sponsors/{sponsor["img"]}" width="190" /></a>')
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<a href="https://www.variomedia.de/"><img title="Variomedia AG" src="https://www.structlog.org/en/25.5.0/_static/sponsors/Variomedia.svg" width="190" /></a>
<a href="https://tidelift.com/?utm_source=lifter&utm_medium=referral&utm_campaign=hynek"><img title="Tidelift" src="https://www.structlog.org/en/25.5.0/_static/sponsors/Tidelift.svg" width="190" /></a>
<a href="https://privacy-solutions.org/"><img title="Privacy Solutions" src="https://www.structlog.org/en/25.5.0/_static/sponsors/Privacy-Solutions.svg" width="190" /></a>
<a href="https://filepreviews.io/"><img title="FilePreviews" src="https://www.structlog.org/en/25.5.0/_static/sponsors/FilePreviews.svg" width="190" /></a>
<a href="https://polar.sh/"><img title="Polar" src="https://www.structlog.org/en/25.5.0/_static/sponsors/Polar.svg" width="190" /></a>
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<p align="center">
   <strong>Please consider <a href="https://github.com/sponsors/hynek">joining them</a> to help make <em>structlog</em>’s maintenance more sustainable!</strong>
</p>

## 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](https://twitter.com/sirupsen/status/638330548361019392) structured logging [packages across ecosystems](https://github.com/sirupsen/logrus).

## Project Links

- [**Get Help**](https://stackoverflow.com/questions/tagged/structlog) (use the *structlog* tag on Stack Overflow)
- [**PyPI**](https://pypi.org/project/structlog/)
- [**GitHub**](https://github.com/hynek/structlog)
- [**Documentation**](https://www.structlog.org/)
- [**Changelog**](https://github.com/hynek/structlog/tree/main/CHANGELOG.md)
- [**Third-party Extensions**](https://github.com/hynek/structlog/wiki/Third-party-Extensions)


## *structlog* for Enterprise

Available as part of the [Tidelift Subscription](https://tidelift.com/?utm_source=lifter&utm_medium=referral&utm_campaign=hynek).

The maintainers of *structlog* and thousands of other packages are working with Tidelift to deliver commercial support and maintenance for the open source packages you use to build your applications.
Save time, reduce risk, and improve code health, while paying the maintainers of the exact packages you use.


## Release Information

### Deprecated

- `structlog.dev.ConsoleRenderer()`'s *pad_event* argument has been renamed to *pad_event_to* to differentiate it from the boolean *pad_level* argument.
  *pad_event* is now deprecated.


### Added

- Added `structlog.dev.ConsoleRenderer.get_active()` that returns the currently active `structlog.dev.ConsoleRenderer()`.
  [#749](https://github.com/hynek/structlog/pull/749)

- `structlog.dev.ConsoleRenderer()` now supports setting the `exception_formatter` attribute.

  You can now disable the pretty-printing of exceptions by setting it to `structlog.dev.plain_traceback`:

  ```python
  cr = structlog.dev.ConsoleRenderer.get_active()
  cr.exception_formatter = structlog.dev.plain_traceback
  ```

  Same goes for *sort_keys*, *columns*, *colors*, *force_colors*, *level_styles*, *pad_event_to*, *event_key*, *timestamp_key*, and *repr_native_str*.

  [#749](https://github.com/hynek/structlog/pull/749)
  [#756](https://github.com/hynek/structlog/pull/756)
  [#757](https://github.com/hynek/structlog/pull/757)
  [#759](https://github.com/hynek/structlog/pull/759)

- Added `structlog.dev.ConsoleRenderer.get_default_column_styles()` for reuse the default column styles.
  [#741](https://github.com/hynek/structlog/pull/741)

- `structlog.testing.capture_logs()` now optionally accepts *processors* to apply before capture.
  [#728](https://github.com/hynek/structlog/pull/728)

- `structlog.dev.RichTracebackFormatter` now exposes the upstream *code_width* parameter.
  Default *width* is now `None` for full terminal width.
  Full terminal width is now handled by Rich itself, bringing support for reflow and `COLUMN` environment variable.
  Passing `-1` for *width* is now deprecated and automatically replaced by `None`.
  [#717](https://github.com/hynek/structlog/pull/717)

- Native loggers now allow the passing of a dictionary for dictionary-based interpolation `log.info("hello %(name)s!", {"name": "world"})`.
  [#748](https://github.com/hynek/structlog/pull/748)

- On Python 3.11+, `structlog.processors.CallsiteParameterAdder` now supports `CallsiteParameter.QUAL_NAME` that adds the qualified name of the callsite, including scope and class names.
  This is only available for *structlog*-originated events since the standard library has no equivalent.

- `structlog.stdlib.LoggerFactory` now supports the *stacklevel* parameter.
  [#763](https://github.com/hynek/structlog/pull/763)


### Changed

- `structlog.dev.rich_traceback()` now throws a more helpful error when Rich is missing.
  [#735](https://github.com/hynek/structlog/pull/735)


### Fixed

- `structlog.processors.MaybeTimeStamper` now respects the *key* argument when determining whether to overwrite the timestamp field.
  [#747](https://github.com/hynek/structlog/pull/747)

- `structlog.tracebacks.extract()` no longer raises a `RecursionError` when the cause chain of an exception contains itself.
  [#739](https://github.com/hynek/structlog/pull/739)

- Default config now respects `FORCE_COLOR` on Windows.
  [#758](https://github.com/hynek/structlog/pull/758)


---

[Full Changelog →](https://www.structlog.org/en/stable/changelog.html)


## Credits

*structlog* is written and maintained by [Hynek Schlawack](https://hynek.me/).
The idea of bound loggers is inspired by previous work by [Jean-Paul Calderone](https://github.com/exarkun) and [David Reid](https://github.com/dreid).

The development is kindly supported by my employer [Variomedia AG](https://www.variomedia.de/), *structlog*’s [Tidelift subscribers](https://tidelift.com/?utm_source=lifter&utm_medium=referral&utm_campaign=hynek), and all my amazing [GitHub Sponsors](https://github.com/sponsors/hynek).

The logs-loving beaver logo has been contributed by [Lynn Root](https://www.roguelynn.com).