structlog makes structured logging in Python easy by augmenting your existing logger. It allows you to split your log entries up into key/value pairs and build them incrementally without annoying boilerplate code.

>>> from structlog import get_logger
>>> log = get_logger()
>>> log = log.bind(user='anonymous', some_key=23)
>>> log = log.bind(user='hynek', another_key=42)
>>> log.info('user.logged_in', happy=True)
some_key=23 user='hynek' another_key=42 happy=True event='user.logged_in'

It's dual-licensed under Apache License, version 2 and MIT, available from PyPI, the source code can be found on GitHub, the documentation at http://www.structlog.org/.

structlog targets Python 2.6, 2.7, 3.3, 3.4, and PyPy with no additional dependencies for core functionality.

If you need any help, visit us on #structlog on Freenode!