Python programming (GUI)
In comparison to Kivy and PyQT, PyGUI is relatively simple and works only for the Mac, Windows, and Unix platforms. PyGUI was developed in New Zealand at the University of Canterbury and focuses on fitting into the Python ecosystem in the simplest way possible. The MVC framework has several main aims, one of which is to put the smallest possible amount of code between Python applications and the underlying GUI so an app's display would always be a reflection of the platform's native GUI. When you need a quick and easy way to pick up GUI, try PyGUI.
PyGObject (or "PyGi")
PyGObject allows you to write Python apps for the GNOME project or Python applications using GTK+. The module includes bindings to GObject, the C cross-platform library offering a baseless to a wider code base and common types. It has been used in a variety of projects such as the GIMP image manipulator, which GTK+ was built for. GTK+ is free, offering a full cross-platform widget toolkit for GUI capability in a wide variety of Windows/Mac, OSX and Linux applications.
Pyforms is one of the newer frameworks and functions as a Python 2.7/3.x cross-environment framework that helps develop GUI applications. Pyforms encourages easy code reusability and is a modular platform. It offers a reasonably large collection of 22 controls based on a ControlBase object, including a web browser, OpenGL, and a video player. Pyforms is based on PyQT, OpenGL, and various other libraries. You can take a look at the online Pyforms docs to help you figure out this platform.
Kivy is a liberal MIT-licensed project which offers native multi-touch for each platform, as well as Android and iOS. It is based on OpenGL ES 2 and is highly useful for game development, as it's an event-driven framework situated around the main loop. Your app can add callbacks from the main loop on a scheduled basis or using a one-off trigger. Kivy can help you create pretty much anything from animation to widgets and offers its own language to describe the user interface and interactions. Kivy is extremely useful if you're looking to outsource development of a cross-platform graphical app or a generally powerful cross-platform GUI.
Multiple books have been written about wxPython so although it's not ready for Python 3 yet, it is worth describing. Based on wxWidgets, a cross-platform C++ GUI library, wxPython includes standard dialogs, a 2D path drawing API, support for various file formats, dockable windows, and widgets for text editing and word processing. It comes with a range of tutorials and demos developed over more than two decades, so it's no surprise that wxPython is one of the most popular frameworks. You can find out more on its wiki.
Written in C++, Qt is a cross-platform framework that's multi-licensed. Qt is a longer-running tool and was previously owned by Nokia. The popular, multi-industry library of tools and APIs covers many platforms, including mobile. Gadgets such as SatNavs and many other which have GUI are often based on Qt.