tensorflow保存变量出现错误（提示不能save)

错误名称：Tensorflow - ValueError: Parent directory of trained_variables.ckpt doesn’t exist, can’t save

This is my line of code :

saver.save(sess, "trained_variables.ckpt")

出现上述错误，解决方案如下：
１）该路径应为：＂．／trained_variables.ckpt＂
２）I’ve put the absoluth path of the file instead of the bare filename and it worked. This is the final code

saver.save(sess, os.path.join(os.getcwd(), 'trained_variables2.ckpt'))

３）

save_path = 'checkpoints/'
model_name = 'my_model'
if not os.path.exists(save_path):
os.makedirs(save_path)
...
saver = tf.train.Saver()
save_path_full = os.path.join(save_path, model_name)
with tf.Session() as sess:
...
saver.save(sess, save_path_full)`