题意：在OPENAI Baselines中保存模型
问题背景：
Openai Baselines save the trained model with the following command,
OpenAI Baselines 使用以下命令保存训练好的模型：
python -m baselines.run --alg=ppo2 --env=PongNoFrameskip-v4 --num_timesteps=2e7 --save_path=~/models/pong_20M_ppo2
But the saved trained model is not in the form of,
但是保存的训练模型并不是以下形式：
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.
-
.
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.ckpt.data
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checkpoint
which it was in this form in the earlier versions. How can we save the model as ., ., . and checkpoint format?
在早期版本中模型是以这种形式保存的。我们如何将模型保存为 .、.、. 和检查点格式？
问题解决：
I've encountered the same problem and I've solved the problem by making a little adjustment to the baselines code.
“我遇到了同样的问题，并通过对 baselines 代码进行一些小调整解决了这个问题。”
There are two pairs of methods in baselines for saving and loading models(the save_state&load_state pair and the save_variables&loas_variables pair) and you can see it in baselines/common/tf_util.py(line325~line372).
在 baselines 中有两对用于保存和加载模型的方法（save_state 和 load_state 这一对，以及 save_variables 和 load_variables 这一对），你可以在 baselines/common/tf_util.py 文件的第 325 行到第 372 行看到这些方法。
For the latest version of baselines, the save_state&load_state pair which saves and loads models in the ., ., . and checkpoint format has been abandoned, so you need to re-enable the save_state&load_state pair.
在最新版本的 baselines 中，save_state 和 load_state 这对用于以 .、.、. 和检查点格式保存和加载模型的方法已被弃用，因此你需要重新启用 save_state 和 load_state 这对方法。
Take ppo2 for example, in baselines/ppo2/, make the following replacement: in line 125, replace
“以 ppo2 为例，在 `baselines/ppo2/` 文件中，进行以下替换：在第 125 行，将”
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self.save = (save_variables, sess=sess)
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self.load = (load_variables, sess=sess)
with 用以下语句替换
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self.save = (save_state, sess=sess)
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self.load = (load_state, sess=sess)
and in line 4, replace 将第4行的以下语句
from baselines.common.tf_util import get_session, save_variables, load_variables
with 用以下语句替换
from baselines.common.tf_util import get_session, save_state, load_state
this will replace the save_variables&loas_variables pair with the save_state&load_state pair.
“这将把 `save_variables` 和 `load_variables` 这对方法替换为 `save_state` 和 `load_state` 这对方法。”
hope this would help you. 希望对你有帮助.
