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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def derivative(self, point):
 r"""The derivative operator. ``DistOperator(y).derivative(z)(x) == ((y - z) / y.dist(z)).inner(x)`` This is only applicable in inner product spaces. Parameters x : `domain` `element-like` Point in which to take the derivative. Returns ------- derivative : `InnerProductOperator` Raises ------ ValueError If ``point == self.vector``, in which case the derivative is not well defined in the Frechet sense. Notes ----- The derivative cannot be written in a general sense except in Hilbert spaces, in which case it is given by .. math:: (D d(\cdot, y))(z)(x) = \langle (y-z) / d(y, z), x \rangle Examples -------- 1.0 """

        point = self.domain.element(point)
        diff = point - self.vector
        dist = self.vector.dist(point)
        if dist == 0:
            raise ValueError('not differentiable at the reference vector {!r}'
                             ''.format(self.vector))

        return InnerProductOperator(diff / dist)