util.py模块代码：
"""
Helpers for dealing with vectorized environments.
"""
from collections import OrderedDict
import gym
import numpy as np
def copy_obs_dict(obs):
"""
Deep-copy an observation dict.
"""
return {k: np.copy(v) for k, v in obs.items()}
def dict_to_obs(obs_dict):
"""
Convert an observation dict into a raw array if the
original observation space was not a Dict space.
"""
if set(obs_dict.keys()) == {None}:
return obs_dict[None]
return obs_dict
def obs_space_info(obs_space):
"""
Get dict-structured information about a gym.Space.
Returns:
A tuple (keys, shapes, dtypes):
keys: a list of dict keys.
shapes: a dict mapping keys to shapes.
dtypes: a dict mapping keys to dtypes.
"""
if isinstance(obs_space, gym.spaces.Dict):
assert isinstance(obs_space.spaces, OrderedDict)
subspaces = obs_space.spaces
elif isinstance(obs_space, gym.spaces.Tuple):
assert isinstance(obs_space.spaces, tuple)
subspaces = {i: obs_space.spaces[i] for i in range(len(obs_space.spaces))}
else:
subspaces = {None: obs_space}
keys = []
shapes = {}
dtypes = {}
for key, box in subspaces.items():
keys.append(key)
shapes[key] = box.shape
dtypes[key] = box.dtype
return keys, shapes, dtypes
def obs_to_dict(obs):
"""
Convert an observation into a dict.
"""
if isinstance(obs, dict):
return obs
return {None: obs}函数：
def copy_obs_dict(obs):def obs_to_dict(obs_dict):假设传入的observation都是dict类型的。
在函数
obs_to_dict中，如果传入的observation不是dict类型的则将其转为dict类型，此时的key值设置为None。
函数
def dict_to_obs(obs_dict)假设输入的是key为None的dict类型的observation，将其dict类型转为np.array类型的observation。
如果输入的不是key为None的dict类型的observation则直接将其返回。
函数
def obs_space_info(obs_space):输入参数为observation的spaces变量。
if isinstance(obs_space, gym.spaces.Dict):
assert isinstance(obs_space.spaces, OrderedDict)
subspaces = obs_space.spaces
elif isinstance(obs_space, gym.spaces.Tuple):
assert isinstance(obs_space.spaces, tuple)
subspaces = {i: obs_space.spaces[i] for i in range(len(obs_space.spaces))}
else:
subspaces = {None: obs_space}首先将env.observation_sapce.spaces变量进行判断，将其转为dict类型。
对env.observation_space.spaces进行信息提取，得到：
Returns:
A tuple (keys, shapes, dtypes):
keys: a list of dict keys.
shapes: a dict mapping keys to shapes.
dtypes: a dict mapping keys to dtypes.最后返回信息的形式为tuple类型。
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