如何在Tensorflow保存pb文件之前访问文件夹名称？

import tensorflow as tf
import os

# 定义模型
x = tf.placeholder(tf.float32, name='input')
y = tf.add(x, 1, name='output')

# 定义变量
var1 = tf.Variable(0, name='var1')
var2 = tf.Variable(1, name='var2')

saver = tf.train.Saver()

with tf.Session() as sess:
    # 初始化变量
    sess.run(tf.global_variables_initializer())

    # 保存模型
    save_path = saver.save(sess, os.path.join(os.path.dirname(__file__), 'model.pb'))
    print("Model saved in file: %s" % save_path)