(self)
return self._rank
Returns the rank of the Prufer sequence.

        Examples
        ========

        >>> from sympy.combinatorics.prufer import Prufer
        >>> p = Prufer([[0, 3], [1, 3], [2, 3], [3, 4], [4, 5]])
        >>> p.rank
        778
        >>> p.next(1).rank
        779
        >>> p.prev().rank
        777

        See Also
        ========

        prufer_rank, next, prev, size
Returns the rank of the Prufer sequence.
Returns the rank of the Prufer sequence .
def rank(self):
        """Returns the rank of the Prufer sequence.

        Examples
        ========

        >>> from sympy.combinatorics.prufer import Prufer
        >>> p = Prufer([[0, 3], [1, 3], [2, 3], [3, 4], [4, 5]])
        >>> p.rank
        778
        >>> p.next(1).rank
        779
        >>> p.prev().rank
        777

        See Also
        ========

        prufer_rank, next, prev, size

        """
        if self._rank is None:
            self._rank = self.prufer_rank()
        return self._rank
def rank ( self ) : if self . _rank is None : self . _rank = self . prufer_rank ( ) return self . _rank