PythonWin is many things. As we discuss in Chapter 20, one of PythonWin’s major roles is to be a Python interface to the Microsoft Foundation Classes, allowing an application to take advantage of some of the more esoteric user interface features available on Windows.
PythonWin is almost a sample application for these MFC extensions. Over time, it has slowly developed features that make it useful as an IDE. As time goes on, we can expect these features to improve.