def parent(self):
        """A new URL with last part of path removed and cleaned up query and
        fragment.

        """
        path = self.raw_path
        if not path or path == "/":
            if self.raw_fragment or self.raw_query_string:
                return URL(self._val._replace(query="", fragment=""), encoded=True)
            return self
        parts = path.split("/")
        val = self._val._replace(path="/".join(parts[:-1]), query="", fragment="")
        return URL(val, encoded=True)
A new URL with last part of path removed and cleaned up query and
        fragment.