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from collections import OrderedDict | |
from typing import Any, Callable, List, Optional, Sequence, Type, Union | |
import gym | |
import numpy as np | |
from stable_baselines3.common.vec_env.base_vec_env import VecEnv, VecEnvIndices, VecEnvObs, VecEnvStepReturn | |
from stable_baselines3.common.vec_env.util import dict_to_obs, obs_space_info | |
import torch | |
class MyDummyVecEnv(VecEnv): | |
""" | |
Creates a simple vectorized wrapper for multiple environments, calling each environment in sequence on the current | |
Python process. This is useful for computationally simple environment such as ``cartpole-v1``, | |
as the overhead of multiprocess or multithread outweighs the environment computation time. | |
This can also be used for RL methods that | |
require a vectorized environment, but that you want a single environments to train with. | |
:param env_fns: a list of functions | |
that return environments to vectorize | |
""" | |
def __init__(self, env_fns: List[Callable[[], gym.Env]], device): | |
self.envs = [fn() for fn in env_fns] | |
env = self.envs[0] | |
VecEnv.__init__(self, len(env_fns), env.observation_space, env.action_space) | |
obs_space = env.observation_space | |
self.keys, shapes, dtypes = obs_space_info(obs_space) | |
self.device = device | |
self.buf_obs = OrderedDict( | |
[(k, torch.zeros((self.num_envs,) + tuple(shapes[k]), dtype=torch.float, device=self.device)) for k in self.keys]) | |
self.buf_dones = np.zeros((self.num_envs,), dtype=bool) | |
self.buf_rews = np.zeros((self.num_envs,), dtype=np.float32) | |
self.buf_infos = [{} for _ in range(self.num_envs)] | |
self.actions = None | |
def step_async(self, actions: np.ndarray) -> None: | |
self.actions = actions | |
def step_wait(self) -> VecEnvStepReturn: | |
for env_idx in range(self.num_envs): | |
obs, self.buf_rews[env_idx], self.buf_dones[env_idx], self.buf_infos[env_idx] = self.envs[env_idx].step( | |
self.actions[env_idx] | |
) | |
if self.buf_dones[env_idx]: | |
# save final observation where user can get it, then reset | |
self.buf_infos[env_idx]["terminal_observation"] = obs | |
obs = self.envs[env_idx].reset() | |
self._save_obs(env_idx, obs) | |
return (self._obs_from_buf(), self.buf_rews, self.buf_dones, self.buf_infos) | |
def seed(self, seed: Optional[int] = None) -> List[Union[None, int]]: | |
seeds = list() | |
for idx, env in enumerate(self.envs): | |
seeds.append(env.seed(seed + idx)) | |
return seeds | |
def reset(self) -> VecEnvObs: | |
for env_idx in range(self.num_envs): | |
obs = self.envs[env_idx].reset() | |
self._save_obs(env_idx, obs) | |
return self._obs_from_buf() | |
def close(self) -> None: | |
for env in self.envs: | |
env.close() | |
def get_images(self) -> Sequence[np.ndarray]: | |
return [env.render(mode="rgb_array") for env in self.envs] | |
def render(self, mode: str = "human") -> Optional[np.ndarray]: | |
""" | |
Gym environment rendering. If there are multiple environments then | |
they are tiled together in one image via ``BaseVecEnv.render()``. | |
Otherwise (if ``self.num_envs == 1``), we pass the render call directly to the | |
underlying environment. | |
Therefore, some arguments such as ``mode`` will have values that are valid | |
only when ``num_envs == 1``. | |
:param mode: The rendering type. | |
""" | |
if self.num_envs == 1: | |
return self.envs[0].render(mode=mode) | |
else: | |
return super().render(mode=mode) | |
def _save_obs(self, env_idx: int, obs: VecEnvObs) -> None: | |
for key in self.keys: | |
self.buf_obs[key][env_idx] = torch.from_numpy(obs[key]).to(self.device, non_blocking=True) | |
def _obs_from_buf(self) -> VecEnvObs: | |
return dict_to_obs(self.observation_space, self.buf_obs) | |
def get_attr(self, attr_name: str, indices: VecEnvIndices = None) -> List[Any]: | |
"""Return attribute from vectorized environment (see base class).""" | |
target_envs = self._get_target_envs(indices) | |
return [getattr(env_i, attr_name) for env_i in target_envs] | |
def set_attr(self, attr_name: str, value: Any, indices: VecEnvIndices = None) -> None: | |
"""Set attribute inside vectorized environments (see base class).""" | |
target_envs = self._get_target_envs(indices) | |
for env_i in target_envs: | |
setattr(env_i, attr_name, value) | |
def env_method(self, method_name: str, *method_args, indices: VecEnvIndices = None, **method_kwargs) -> List[Any]: | |
"""Call instance methods of vectorized environments.""" | |
target_envs = self._get_target_envs(indices) | |
return [getattr(env_i, method_name)(*method_args, **method_kwargs) for env_i in target_envs] | |
def env_is_wrapped(self, wrapper_class: Type[gym.Wrapper], indices: VecEnvIndices = None) -> List[bool]: | |
"""Check if worker environments are wrapped with a given wrapper""" | |
target_envs = self._get_target_envs(indices) | |
# Import here to avoid a circular import | |
from stable_baselines3.common import env_util | |
return [env_util.is_wrapped(env_i, wrapper_class) for env_i in target_envs] | |
def _get_target_envs(self, indices: VecEnvIndices) -> List[gym.Env]: | |
indices = self._get_indices(indices) | |
return [self.envs[i] for i in indices] | |