tf while loop issues

gistfile1.txt

   def while_test(lconfig):
        """ Simple tensorflow while_loop test within ADNN

        Not to be used as an actual loss
        """

        def _cond(i_loop, d):
            return tf.less(i_loop, 10)

        def _body(i_loop, d):
            return i_loop+1, d * 1.2

        with tf.control_dependencies([pred_depth]):
            _, new_d = tf.while_loop(
                    _cond, _body,
                    (0, pred_depth),
                    back_prop=False,
                    parallel_iterations=1,
                    name='while_test',
                    )
        loss = tf.reduce_mean(new_d)
        #loss = tf.reduce_mean(pred_depth)
        loss = tf.Print(loss, [loss], message='while_test_loss')
        return loss