In ASCII, validating a name isn't too difficult: just make sure all the characters are alphabetical.
But what about in Unicode (utf-8) ? How can I make sure there are no commas or underscores (outside of ASCII scope) in a given string?
(ideally in Python)
Just convert bytestring (your utf-8) to unicode objects and check if all characters are alphabetic:
s.isalpha()
This method is locale-dependent for bytestrings.