def python_module_name(self) -> str:
        """
        Returns the name of the Python module that this instance refers to,
        in dotted Python module notation, or a blank string if it doesn't.
        """
        if not self.is_python:
            return ""
        filepath = self.source_filename_rel_python_root
        dirs_and_base = splitext(filepath)[0]
        dir_and_file_parts = dirs_and_base.split(sep)
        return ".".join(dir_and_file_parts)