def _is_control(self, char):
        """Checks whether `chars` is a control character."""
        # These are technically control characters but we count them as whitespace
        # characters.
        if char == "\t" or char == "\n" or char == "\r":
            return False
        cat = unicodedata.category(char)
        if cat in ("Cc", "Cf"):
            return True
        return False
Checks whether `chars` is a control character.
examples/research_projects/anytext/anytext.py