Source code for momba.gym.env

# -*- coding:utf-8 -*-
#
# Copyright (C) 2019-2021, Saarland University
# Copyright (C) 2019-2021, Maximilian Köhl <koehl@cs.uni-saarland.de>

from __future__ import annotations

import typing as t

import gym
import numpy

from gym import spaces
from gym.error import UnsupportedMode

from . import abstract


class Renderer(t.Protocol):
    def render(self, state: abstract.StateVector, mode: str) -> None:
        raise NotImplementedError()


[docs]class MombaEnv(gym.Env): # type: ignore """ Implementation of an OpenAI Gym environment. Arguments: explorer: The :class:`abstract.Explorer` to use. renderer: An optional renderer for the OpenAI Gym API. """ explorer: abstract.Explorer action_space: gym.Space # type: ignore observation_space: gym.Space # type: ignore renderer: t.Optional[Renderer] def __init__( self, explorer: abstract.Explorer, *, renderer: t.Optional[Renderer] = None ) -> None: super().__init__() self.explorer = explorer self.action_space = spaces.Discrete(self.explorer.num_actions) self.observation_space = spaces.Box( low=float("-inf"), high=float("inf"), shape=(self.explorer.num_features,) ) self.renderer = renderer @property def available_actions(self) -> numpy.ndarray: # type: ignore return numpy.array(self.explorer.available_actions) @property def available_transitions(self) -> t.Sequence[abstract.Transition]: return self.explorer.available_transitions @property def is_done(self) -> bool: return self.explorer.has_terminated @property def state_vector(self) -> numpy.ndarray: # type: ignore return numpy.array(self.explorer.state_vector)
[docs] def fork(self) -> MombaEnv: """Forks the environment.""" return MombaEnv(self.explorer.fork(), renderer=self.renderer)
[docs] def step(self, action: int) -> t.Tuple[numpy.ndarray, float, bool, t.Any]: # type: ignore """Takes a decision in response to the last observation.""" reward = self.explorer.step(action) state = numpy.array(self.explorer.state_vector) return state, reward, self.explorer.has_terminated, {}
[docs] def reset(self) -> numpy.ndarray: # type: ignore """Resets the environment to an initial state and returns an initial observation.""" self.explorer.reset() return numpy.array(self.explorer.state_vector)
[docs] def render(self, mode: str = "human") -> None: """Renders the environment assuming a :code:`render` has been supplied.""" if self.renderer is None: raise UnsupportedMode("`MombaGym` does not support rendering") else: self.renderer.render(self.explorer.state_vector, mode)