gym.wrappers.Monitor报错，无法使用

使用gym中的录制功能，报错，具体：

 

>>> import gym

>>> gym.wrappers.Monitor
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: module 'gym.wrappers' has no attribute 'Monitor'

 

 

 

经过网上查询知道在gym的0.21以上版本API进行了更改，gym.wrappers.Monitor由

gym.wrappers.RecordVideo 和 gym.wrappers.RecordEpisodeStatistics 所替代：

 

注意，使用之前需要安装依赖：

pip install moviepy

 

import gym
env = gym.make("BipedalWalker-v3",render_mode = 'human')

env = gym.wrappers.RecordEpisodeStatistics(env)
env = gym.wrappers.RecordVideo(env, f"videos/{gym.__version__}")

 

 

===================================================

 

 

关于gym.wrappers.RecordEpisodeStatistics的帮助文档：

 

class RecordEpisodeStatistics(gym.core.Wrapper)
 |  RecordEpisodeStatistics(*args, **kwds)
 |  
 |  This wrapper will keep track of cumulative rewards and episode lengths.
 |  
 |  At the end of an episode, the statistics of the episode will be added to ``info``
 |  using the key ``episode``. If using a vectorized environment also the key
 |  ``_episode`` is used which indicates whether the env at the respective index has
 |  the episode statistics.
 |  
 |  After the completion of an episode, ``info`` will look like this::
 |  
 |      >>> info = {
 |      ...     ...
 |      ...     "episode": {
 |      ...         "r": "<cumulative reward>",
 |      ...         "l": "<episode length>",
 |      ...         "t": "<elapsed time since instantiation of wrapper>"
 |      ...     },
 |      ... }
 |  
 |  For a vectorized environments the output will be in the form of::
 |  
 |      >>> infos = {
 |      ...     ...
 |      ...     "episode": {
 |      ...         "r": "<array of cumulative reward>",
 |      ...         "l": "<array of episode length>",
 |      ...         "t": "<array of elapsed time since instantiation of wrapper>"
 |      ...     },
 |      ...     "_episode": "<boolean array of length num-envs>"
 |      ... }
 |  
 |  Moreover, the most recent rewards and episode lengths are stored in buffers that can be accessed via
 |  :attr:`wrapped_env.return_queue` and :attr:`wrapped_env.length_queue` respectively. 

 

 

可以看到，gym.wrappers.RecordEpisodeStatistics 在运行过程中进行统计然后在info中进行显示，这样的操作会占用一定的计算资源，如果没有必要使用则不需要使用。

 

 

===================================================

 

参考：

https://zhuanlan.zhihu.com/p/569710619