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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 rotation_and_translation_from_matrix(matrix):
 """Helper to convert 4x4 matrix to rotation matrix and translation vector. Parameters matrix : :obj:`numpy.ndarray` of float 4x4 rigid transformation matrix to be converted. Returns ------- :obj:`tuple` of :obj:`numpy.ndarray` of float A 3x3 rotation matrix and a 3-entry translation vector. Raises ------ ValueError If the incoming matrix isn't a 4x4 ndarray. """

        if not isinstance(matrix, np.ndarray) or \
                matrix.shape[0] != 4 or matrix.shape[1] != 4:
            raise ValueError('Matrix must be specified as a 4x4 ndarray')
        rotation = matrix[:3,:3]
        translation = matrix[:3,3]
        return rotation, translation