In modern Integrated Development Environments (IDEs) like the PyDev plugin in Eclipse or another IDE such as NetBeans, we can set debug watches to monitor the state of our GUI during the execution of our code.
This is very similar to the Microsoft IDEs of Visual Studio and the more recent versions of Visual Studio.NET.
In this recipe, we will reuse the Python GUI we developed in earlier recipes. We are stepping through the code we previously developed and setting debug watches.
Note
While this recipe applies to the PyDev plugin in the Java-based Eclipse IDE, its principles also apply to many modern IDEs.
The first position where we might wish to place a breakpoint is at the place where we make our GUI visible by calling the tkinter main event loop.
The green balloon symbol on the left is a breakpoint in PyDev/Eclipse. When we execute our code in debug mode, once...