Spaces:
Sleeping
Sleeping
"""Wrapper for transforming observations.""" | |
from typing import Any, Callable | |
import gym | |
class TransformObservation(gym.ObservationWrapper): | |
"""Transform the observation via an arbitrary function :attr:`f`. | |
The function :attr:`f` should be defined on the observation space of the base environment, ``env``, and should, ideally, return values in the same space. | |
If the transformation you wish to apply to observations returns values in a *different* space, you should subclass :class:`ObservationWrapper`, implement the transformation, and set the new observation space accordingly. If you were to use this wrapper instead, the observation space would be set incorrectly. | |
Example: | |
>>> import gym | |
>>> import numpy as np | |
>>> env = gym.make('CartPole-v1') | |
>>> env = TransformObservation(env, lambda obs: obs + 0.1*np.random.randn(*obs.shape)) | |
>>> env.reset() | |
array([-0.08319338, 0.04635121, -0.07394746, 0.20877492]) | |
""" | |
def __init__(self, env: gym.Env, f: Callable[[Any], Any]): | |
"""Initialize the :class:`TransformObservation` wrapper with an environment and a transform function :param:`f`. | |
Args: | |
env: The environment to apply the wrapper | |
f: A function that transforms the observation | |
""" | |
super().__init__(env) | |
assert callable(f) | |
self.f = f | |
def observation(self, observation): | |
"""Transforms the observations with callable :attr:`f`. | |
Args: | |
observation: The observation to transform | |
Returns: | |
The transformed observation | |
""" | |
return self.f(observation) | |