The PySide project provides LGPL-licensed Python bindings for the Qt (Qt is a framework for cross-platform UI and applications).
PySide bindings allow both free open source and proprietary software development and ultimately aim to support all of the platforms as Qt itself.
Official site: https://www.pyside.org/
* Docs and Tutorials: https://developer.qt.nokia.com/wiki/PySideDocumentation
* Examples: https://qt.gitorious.org/pyside/pyside-examples