Adding Custom Menu "Run Script" Button Causes Duplicate Is there a way to use the Blender Text Editor for adding a custom menu and not get a duplicate every time I click on "Run Script" to test the menu? For example, in the text editor, load the template like so:

Template -> Python -> UI Menu

Then notice every time you press "Run Script" you get another menu in your main menu bar. How can I update my menu without getting a duplicate?

I tried simply commenting out register() but then new updates don't show up.
Execute Reload Scripts F8 first before re-running the script. 

I think a custom menu function is supposed to run within an addon, where register() and unregister() are run in pairs. Each script execution yields different instance of each functions, even if their name doesn't change across each execution. So unless there is a way to check existing draw functions within a class by name (which I haven't found yet), Reload Scripts or restarting Blender is the way to go.