Normalize the path. Turn /file/title/../author to /file/author

        :return: <self>

def normalize(self):
        """
        Normalize the path. Turn /file/title/../author to /file/author

        :return: <self>
        """
        if str(self):
            normalized = normpath(str(self)) + ('/' * self.is_dir)
            if normalized.startswith('//'):  # http://bugs.python.org/636648
                normalized = '/' + normalized.lstrip('/')
            self.load(normalized)
        return self