wxPython is a GUI toolkit, which is developed to be used, as the name states, by the Python programming language. Although Python's standard GUI toolkit is Tkinter, wxPython is gaining a great deal of community support.
wxPython wraps the wxWidget library (also created by wxDesigner) that is written in C++ into Python. This means that wxPython's widgets are cross-platform, so the program will show the GUI objects, no matter if its on Windows, Mac OS or Linux. However, the widgets work extraordinarily well in Windows environments.
These widgets include simple items, such as menus, forms, text fields, cells, buttons, colour pickers among others. The library is also open source, this means that new widgets, objects are created by the open community.
If you have Python installed, then the simple package will be enough for you to set things up. There are many guides and tutorials on the Internet, and the product's page for beginners to start getting a hang on wxPython. If you do not like TkInter widgets or just want something different, this is the toolkit for you.