code: def norm(self, x):
          
          if x not in self:
              raise LinearSpaceTypeError('`x` {!r} is not an element of '
                                         '{!r}'.format(x, self))
          return float(self._norm(x))
docs: Return the norm of ``x``.
  
          Parameters
          ----------
          x : `LinearSpaceElement`
              Element whose norm to compute.
  
          Returns
          -------
          norm : float
              Norm of ``x``.