How to use UTF-8

Screenshot of a code about Valid CharactersSo I downloaded a Programm from Github and wanted to make a change since it wouldnt want to name Files with japanese characters.

So i tried adding UTF-8 to it..... (See Screenshot from above) But since I´ve never written python and only have a beginner Book, I decided to ask my question here. The Code in the Screenshot could be completley wrong since I´ve messed with it. So if you Guys have any Ideas, I will be more than happy to hear them.