code: def l1_distance(t1, t2, name=None):
    
    with tf.name_scope(name, 'l1_distance', [t1, t2]) as scope:
      t1 = tf.convert_to_tensor(t1, name='t1')
      t2 = tf.convert_to_tensor(t2, name='t2')
      sub = tf.subtract(t1, t2)
      reduction_dim = _last_index(sub, 1)
      return tf.reduce_sum(tf.abs(sub), reduction_dim, name=scope)
docs: l1 distance between t1 and t2.
  
    Args:
      t1: A tensor.
      t2: A tensor that is the same size as t1.
      name: Optional name for this op.
    Returns:
      The l1 distance between t1 and t2.