Metadata-Version: 2.1
Name: structlog
Version: 18.2.0
Summary: Structured Logging for Python
Home-page: https://www.structlog.org/
Author: Hynek Schlawack
Author-email: hs@ox.cx
Maintainer: Hynek Schlawack
Maintainer-email: hs@ox.cx
License: MIT or Apache License, Version 2.0
Keywords: logging,structured,structure,log
Classifier: Development Status :: 5 - Production/Stable
Classifier: Intended Audience :: Developers
Classifier: License :: OSI Approved :: Apache Software License
Classifier: License :: OSI Approved :: MIT License
Classifier: Natural Language :: English
Classifier: Operating System :: OS Independent
Classifier: Programming Language :: Python :: 2
Classifier: Programming Language :: Python :: 2.7
Classifier: Programming Language :: Python :: 3
Classifier: Programming Language :: Python :: 3.4
Classifier: Programming Language :: Python :: 3.5
Classifier: Programming Language :: Python :: 3.6
Classifier: Programming Language :: Python :: 3.7
Classifier: Programming Language :: Python :: Implementation :: CPython
Classifier: Programming Language :: Python :: Implementation :: PyPy
Classifier: Programming Language :: Python
Classifier: Topic :: Software Development :: Libraries :: Python Modules
Provides-Extra: dev
Provides-Extra: tests
Provides-Extra: docs
License-File: LICENSE

.. image:: https://www.structlog.org/en/latest/_static/structlog_logo_small.png
   :alt: structlog Logo
   :width: 256px
   :target: https://www.structlog.org/

============================================
``structlog``: Structured Logging for Python
============================================

.. image:: https://readthedocs.org/projects/structlog/badge/?version=stable
   :target: https://www.structlog.org/en/stable/?badge=stable
   :alt: Documentation Status

.. image:: https://travis-ci.org/hynek/structlog.svg?branch=master
   :target: https://travis-ci.org/hynek/structlog

.. image:: https://codecov.io/github/hynek/structlog/branch/master/graph/badge.svg
   :target: https://codecov.io/github/hynek/structlog
   :alt: Test Coverage

.. image:: https://img.shields.io/badge/code%20style-black-000000.svg
   :target: https://github.com/ambv/black
   :alt: Code style: black

.. -begin-short-

``structlog`` makes logging in Python less painful and more powerful by adding structure to your log entries.

It's up to you whether you want ``structlog`` to take care about 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.

.. -end-short-


.. -begin-spiel-

Easier Logging
==============

You can stop writing prose and start thinking in terms of an event that happens in the context of key/value pairs:

.. code-block:: pycon

   >>> from structlog import get_logger
   >>> log = get_logger()
   >>> log.info("key_value_logging", out_of_the_box=True, effort=0)
   2016-04-20 16:20.13 key_value_logging              effort=0 out_of_the_box=True

Each log entry is a meaningful dictionary instead of an opaque string now!


Data Binding
============

Since log entries are dictionaries, you can start binding and re-binding key/value pairs to your loggers to ensure they are present in every following logging call:

.. code-block:: pycon

   >>> log = log.bind(user="anonymous", some_key=23)
   >>> log = log.bind(user="hynek", another_key=42)
   >>> log.info("user.logged_in", happy=True)
   2016-04-20 16:20.13 user.logged_in                 another_key=42 happy=True some_key=23 user='hynek'


Powerful Pipelines
==================

Each log entry goes through a `processor pipeline <https://www.structlog.org/en/stable/processors.html>`_ that is just a chain of functions that receive a dictionary and return a new dictionary that gets fed into the next function.
That allows for simple but powerful data manipulation:

.. code-block:: python

   def timestamper(logger, log_method, event_dict):
       """Add a timestamp to each log entry."""
       event_dict["timestamp"] = time.time()
       return event_dict

There are `plenty of processors <https://www.structlog.org/en/stable/api.html#module-structlog.processors>`_ for most common tasks coming with ``structlog``:

- Collectors of `call stack information <https://www.structlog.org/en/stable/api.html#structlog.processors.StackInfoRenderer>`_ ("How did this log entry happen?"),
- …and `exceptions <https://www.structlog.org/en/stable/api.html#structlog.processors.format_exc_info>`_ ("What happened‽").
- Unicode encoders/decoders.
- Flexible `timestamping <https://www.structlog.org/en/stable/api.html#structlog.processors.TimeStamper>`_.



Formatting
==========

``structlog`` is completely flexible about *how* the resulting log entry is emitted.
Since each log entry is a dictionary, it can be formatted to **any** format:

- A colorful key/value format for `local development <https://www.structlog.org/en/stable/development.html>`_,
- `JSON <https://www.structlog.org/en/stable/api.html#structlog.processors.JSONRenderer>`_ for easy parsing,
- or some standard format you have parsers for like nginx or Apache httpd.

Internally, formatters are processors whose return value (usually a string) is passed into loggers that are responsible for the output of your message.
``structlog`` comes with multiple useful formatters out of-the-box.


Output
======

``structlog`` is also very flexible with the final output of your log entries:

- A **built-in** lightweight printer like in the examples above.
  Easy to use and fast.
- Use the **standard library**'s or **Twisted**'s logging modules for compatibility.
  In this case ``structlog`` works like a wrapper that formats a string and passes them off into existing systems that won't ever know that ``structlog`` even exists.
  Or the other way round: ``structlog`` comes with a ``logging`` formatter that allows for processing third party log records.
- Don't format it to a string at all!
  ``structlog`` passes you a dictionary and you can do with it whatever you want.
  Reported uses cases are sending them out via network or saving them in a database.

.. -end-spiel-

.. -begin-meta-

Getting Help
============

Please use the ``structlog`` tag on `StackOverflow <https://stackoverflow.com/questions/tagged/structlog>`_ to get help.

Answering questions of your fellow developers is also great way to help the project!


Project Information
===================

``structlog`` is dual-licensed under `Apache License, version 2 <https://choosealicense.com/licenses/apache/>`_ and `MIT <https://choosealicense.com/licenses/mit/>`_, available from `PyPI <https://pypi.org/project/structlog/>`_, the source code can be found on `GitHub <https://github.com/hynek/structlog>`_, the documentation at https://www.structlog.org/.

``structlog`` targets Python 2.7, 3.4 and newer, and PyPy.


Release Information
===================

18.2.0 (2018-09-05)
-------------------


Backward-incompatible changes:
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

*none*


Deprecations:
^^^^^^^^^^^^^

*none*


Changes:
^^^^^^^^

- Added ``structlog.stdlib.add_log_level_number()`` processor that adds the level *number* to the event dictionary.
  Can be used to simplify log filtering.
  `#151 <https://github.com/hynek/structlog/pull/151>`_
- ``structlog.processors.JSONRenderer`` now allows for overwriting the *default* argument of its serializer.
  `#77 <https://github.com/hynek/structlog/pull/77>`_
  `#163 <https://github.com/hynek/structlog/pull/163>`_
- Added ``try_unbind()`` that works like ``unbind()`` but doesn't raise a ``KeyError`` if one of the keys is missing.
  `#171 <https://github.com/hynek/structlog/pull/171>`_

`Full changelog <https://www.structlog.org/en/stable/changelog.html>`_.

Authors
=======

``structlog`` is written and maintained by `Hynek Schlawack <https://hynek.me/>`_.
It’s inspired by previous work done by `Jean-Paul Calderone <https://as.ynchrono.us/>`_ and `David Reid <https://dreid.org/>`_.

The development is kindly supported by `Variomedia AG <https://www.variomedia.de/>`_.

A full list of contributors can be found on GitHub’s `overview <https://github.com/hynek/structlog/graphs/contributors>`_.
Some of them disapprove of the addition of thread local context data. :)

The ``structlog`` logo has been contributed by `Russell Keith-Magee <https://github.com/freakboy3742>`_.
