There are two available Python bindings to the Qt framework, PyQt and PySide. PyQt was first released in 1998 but requires a license for commercial projects. Due to this licensing problem, the company developing Qt, then Nokia and now Digia, later developed Python bindings in 2009 called PySide and released it under the more permissive LGPL license.
There are minor differences between the two bindings but the examples developed here will work with either. The following snippet can be used to import whichever Qt binding is installed:
try:
from PySide.QtGui import *
from PySide.QtCore import *
from PySide.QtWebKit import *
except ImportError:
from PyQt4.QtGui import *
from PyQt4.QtCore import *
from PyQt4.QtWebKit import *
Here, if PySide is not available, an ImportError exception will be raised and PyQt will be imported. If PyQt is also unavailable, another ImportError will be raised and the script will exit.
The instructions to download and install each of the Python bindings for Qt are available at http://qt-project.org/wiki/Setting_up_PySide and http://pyqt.sourceforge.net/Docs/PyQt4/installation.html. Depending on the version of Python 3 you are using, there might not be availability yet for the library, but releases are somewhat frequent so you can always check back soon.