Naming convention advice

[Alfalfa]

I recently went over all methods of a project to regroups them by reverse naming, alphabetical order, and type (third party, private, public). Finally I added an underscore in front of all private methods. One of the class is a GUI for preferences (PreferencesForm), which contain only private methods. The class is huge and is only called as a standalone instance, so should I still prefix all methods with an underscore?

You can take a look at the module here:
https://gitlab.com/william.belanger/qtpa...erences.py