Tensorflow 모델 저장 및 복원에 대한 간략한 토론

import tensorflow as tf
import os

def save_model_ckpt(ckpt_file_path):
  x = tf.placeholder(tf.int32, name='x')
  y = tf.placeholder(tf.int32, name='y')
  b = tf.Variable(1, name='b')
  xy = tf.multiply(x, y)
  op = tf.add(xy, b, name='op_to_store')

  sess = tf.Session()
  sess.run(tf.global_variables_initializer())

  path = os.path.dirname(os.path.abspath(ckpt_file_path))
  if os.path.isdir(path) is False:
    os.makedirs(path)

  tf.train.Saver().save(sess, ckpt_file_path)
  
  # test
  feed_dict = {x: 2, y: 3}
  print(sess.run(op, feed_dict))

tf.train.Saver().save(sess, ckpt_file_path, global_step=1000)

tf.train.Saver().save(sess, ckpt_file_path, global_step=1000, write_meta_graph=False)

tf.train.Saver().save(sess, ckpt_file_path, max_to_keep=4, keep_checkpoint_every_n_hours=2)

tf.train.Saver([x, y]).save(sess, ckpt_file_path)

import tensorflow as tf

def restore_model_ckpt(ckpt_file_path):
  sess = tf.Session()
  saver = tf.train.import_meta_graph('./ckpt/model.ckpt.meta') # 加载模型结构
  saver.restore(sess, tf.train.latest_checkpoint('./ckpt')) # 只需要指定目录就可以恢复所有变量信息

  # 直接获取保存的变量
  print(sess.run('b:0'))

  # 获取placeholder变量
  input_x = sess.graph.get_tensor_by_name('x:0')
  input_y = sess.graph.get_tensor_by_name('y:0')
  # 获取需要进行计算的operator
  op = sess.graph.get_tensor_by_name('op_to_store:0')

  # 加入新的操作
  add_on_op = tf.multiply(op, 2)

  ret = sess.run(add_on_op, {input_x: 5, input_y: 5})
  print(ret)

import tensorflow as tf
import os
from tensorflow.python.framework import graph_util

def save_mode_pb(pb_file_path):
  x = tf.placeholder(tf.int32, name='x')
  y = tf.placeholder(tf.int32, name='y')
  b = tf.Variable(1, name='b')
  xy = tf.multiply(x, y)
  # 这里的输出需要加上name属性
  op = tf.add(xy, b, name='op_to_store')

  sess = tf.Session()
  sess.run(tf.global_variables_initializer())

  path = os.path.dirname(os.path.abspath(pb_file_path))
  if os.path.isdir(path) is False:
    os.makedirs(path)

  # convert_variables_to_constants 需要指定output_node_names，list()，可以多个
  constant_graph = graph_util.convert_variables_to_constants(sess, sess.graph_def, ['op_to_store'])
  with tf.gfile.FastGFile(pb_file_path, mode='wb') as f:
    f.write(constant_graph.SerializeToString())

  # test
  feed_dict = {x: 2, y: 3}
  print(sess.run(op, feed_dict))

import tensorflow as tf
from tensorflow.python.platform import gfile

def restore_mode_pb(pb_file_path):
  sess = tf.Session()
  with gfile.FastGFile(pb_file_path, 'rb') as f:
    graph_def = tf.GraphDef()
    graph_def.ParseFromString(f.read())
    sess.graph.as_default()
    tf.import_graph_def(graph_def, name='')

  print(sess.run('b:0'))

  input_x = sess.graph.get_tensor_by_name('x:0')
  input_y = sess.graph.get_tensor_by_name('y:0')

  op = sess.graph.get_tensor_by_name('op_to_store:0')

  ret = sess.run(op, {input_x: 5, input_y: 5})
  print(ret)