This is a python based UI application that can rename a part of a set of files inside a directory based on the provided regular expression. This gives a lot more flexibility compared to other renaming files since it used grouping principle. This had two level of applying the rename, first stage shows who it will be when you rename it, if you are fine with the change you can make it permanent by clicking commit. This avoid the risk of file getting corrupted.
To rename all .py file to .pyc is...