Description:

Most of the commands in Pynsource are wrapped in command objects, which have an execute, undo and redo method.

This is a classic use of the Command design pattern.

Image courtesy of Wikipedia.

The undo operations in Pynsource are currently not implemented, but this will one day get done.

Here is a screenshot of the Pynsource app, which is a free desktop app (Mac, Windows, Linux) for reverse engineering Python source code into UML.

See the source code for Pynsource here on GitHub.