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.
It's licensed under Apache License, version 2, 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, 3.2, 3.3, and PyPy with no additional dependencies for core functionality.
If you need any help, visit us on #structlog on Freenode!