from __future__ import annotations
from typing import Any
import numpy as np
from pettingzoo.utils.env import (
ActionType,
AECEnv,
AECIterable,
AECIterator,
AgentID,
ObsType,
)
from pettingzoo.utils.env_logger import EnvLogger
from pettingzoo.utils.wrappers.base import BaseWrapper
[docs]
class OrderEnforcingWrapper(BaseWrapper[AgentID, ObsType, ActionType]):
"""Checks if function calls or attribute access are in a disallowed order.
The following are raised:
* AttributeError if any of the following are accessed before reset():
rewards, terminations, truncations, infos, agent_selection,
num_agents, agents.
* An error if any of the following are called before reset:
render(), step(), observe(), state(), agent_iter()
* A warning if step() is called when there are no agents remaining.
"""
def __init__(self, env: AECEnv[AgentID, ObsType, ActionType]):
assert isinstance(
env, AECEnv
), "OrderEnforcingWrapper is only compatible with AEC environments"
self._has_reset = False
self._has_updated = False
super().__init__(env)
def __getattr__(self, value: str) -> Any:
"""Raises an error if certain data is accessed before reset."""
if (
value
in {
"rewards",
"terminations",
"truncations",
"infos",
"agent_selection",
"num_agents",
"agents",
}
and not self._has_reset
):
raise AttributeError(f"{value} cannot be accessed before reset")
return super().__getattr__(value)
def render(self) -> None | np.ndarray | str | list:
if not self._has_reset:
EnvLogger.error_render_before_reset()
return super().render()
def step(self, action: ActionType) -> None:
if not self._has_reset:
EnvLogger.error_step_before_reset()
elif not self.agents:
self._has_updated = True
EnvLogger.warn_step_after_terminated_truncated()
else:
self._has_updated = True
super().step(action)
def observe(self, agent: AgentID) -> ObsType | None:
if not self._has_reset:
EnvLogger.error_observe_before_reset()
return super().observe(agent)
def state(self) -> np.ndarray:
if not self._has_reset:
EnvLogger.error_state_before_reset()
return super().state()
def agent_iter(
self, max_iter: int = 2**63
) -> AECOrderEnforcingIterable[AgentID, ObsType, ActionType]:
if not self._has_reset:
EnvLogger.error_agent_iter_before_reset()
return AECOrderEnforcingIterable(self, max_iter)
def reset(self, seed: int | None = None, options: dict | None = None) -> None:
self._has_reset = True
self._has_updated = True
super().reset(seed=seed, options=options)
def __str__(self) -> str:
if hasattr(self, "metadata"):
return (
str(self.env)
if self.__class__ is OrderEnforcingWrapper
else f"{type(self).__name__}<{str(self.env)}>"
)
return repr(self)
class AECOrderEnforcingIterable(AECIterable[AgentID, ObsType, ActionType]):
def __iter__(self) -> AECOrderEnforcingIterator[AgentID, ObsType, ActionType]:
return AECOrderEnforcingIterator(self.env, self.max_iter)
class AECOrderEnforcingIterator(AECIterator[AgentID, ObsType, ActionType]):
def __init__(
self, env: OrderEnforcingWrapper[AgentID, ObsType, ActionType], max_iter: int
):
assert isinstance(
env, OrderEnforcingWrapper
), "env must be wrapped by OrderEnforcingWrapper"
super().__init__(env, max_iter)
def __next__(self) -> AgentID:
agent = super().__next__()
assert (
self.env._has_updated # pyright: ignore[reportGeneralTypeIssues]
), "need to call step() or reset() in a loop over `agent_iter`"
self.env._has_updated = False # pyright: ignore[reportGeneralTypeIssues]
return agent
