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"""A set of functions for checking an environment details. | |
This file is originally from the Stable Baselines3 repository hosted on GitHub | |
(https://github.com/DLR-RM/stable-baselines3/) | |
Original Author: Antonin Raffin | |
It also uses some warnings/assertions from the PettingZoo repository hosted on GitHub | |
(https://github.com/PettingZoo-Team/PettingZoo) | |
Original Author: J K Terry | |
This was rewritten and split into "env_checker.py" and "passive_env_checker.py" for invasive and passive environment checking | |
Original Author: Mark Towers | |
These projects are covered by the MIT License. | |
""" | |
import inspect | |
from copy import deepcopy | |
import numpy as np | |
import gym | |
from gym import logger, spaces | |
from gym.utils.passive_env_checker import ( | |
check_action_space, | |
check_observation_space, | |
env_render_passive_checker, | |
env_reset_passive_checker, | |
env_step_passive_checker, | |
) | |
def data_equivalence(data_1, data_2) -> bool: | |
"""Assert equality between data 1 and 2, i.e observations, actions, info. | |
Args: | |
data_1: data structure 1 | |
data_2: data structure 2 | |
Returns: | |
If observation 1 and 2 are equivalent | |
""" | |
if type(data_1) == type(data_2): | |
if isinstance(data_1, dict): | |
return data_1.keys() == data_2.keys() and all( | |
data_equivalence(data_1[k], data_2[k]) for k in data_1.keys() | |
) | |
elif isinstance(data_1, (tuple, list)): | |
return len(data_1) == len(data_2) and all( | |
data_equivalence(o_1, o_2) for o_1, o_2 in zip(data_1, data_2) | |
) | |
elif isinstance(data_1, np.ndarray): | |
return data_1.shape == data_2.shape and np.allclose( | |
data_1, data_2, atol=0.00001 | |
) | |
else: | |
return data_1 == data_2 | |
else: | |
return False | |
def check_reset_seed(env: gym.Env): | |
"""Check that the environment can be reset with a seed. | |
Args: | |
env: The environment to check | |
Raises: | |
AssertionError: The environment cannot be reset with a random seed, | |
even though `seed` or `kwargs` appear in the signature. | |
""" | |
signature = inspect.signature(env.reset) | |
if "seed" in signature.parameters or ( | |
"kwargs" in signature.parameters | |
and signature.parameters["kwargs"].kind is inspect.Parameter.VAR_KEYWORD | |
): | |
try: | |
obs_1, info = env.reset(seed=123) | |
assert ( | |
obs_1 in env.observation_space | |
), "The observation returned by `env.reset(seed=123)` is not within the observation space." | |
assert ( | |
env.unwrapped._np_random # pyright: ignore [reportPrivateUsage] | |
is not None | |
), "Expects the random number generator to have been generated given a seed was passed to reset. Mostly likely the environment reset function does not call `super().reset(seed=seed)`." | |
seed_123_rng = deepcopy( | |
env.unwrapped._np_random # pyright: ignore [reportPrivateUsage] | |
) | |
obs_2, info = env.reset(seed=123) | |
assert ( | |
obs_2 in env.observation_space | |
), "The observation returned by `env.reset(seed=123)` is not within the observation space." | |
if env.spec is not None and env.spec.nondeterministic is False: | |
assert data_equivalence( | |
obs_1, obs_2 | |
), "Using `env.reset(seed=123)` is non-deterministic as the observations are not equivalent." | |
assert ( | |
env.unwrapped._np_random.bit_generator.state # pyright: ignore [reportPrivateUsage] | |
== seed_123_rng.bit_generator.state | |
), "Mostly likely the environment reset function does not call `super().reset(seed=seed)` as the random generates are not same when the same seeds are passed to `env.reset`." | |
obs_3, info = env.reset(seed=456) | |
assert ( | |
obs_3 in env.observation_space | |
), "The observation returned by `env.reset(seed=456)` is not within the observation space." | |
assert ( | |
env.unwrapped._np_random.bit_generator.state # pyright: ignore [reportPrivateUsage] | |
!= seed_123_rng.bit_generator.state | |
), "Mostly likely the environment reset function does not call `super().reset(seed=seed)` as the random number generators are not different when different seeds are passed to `env.reset`." | |
except TypeError as e: | |
raise AssertionError( | |
"The environment cannot be reset with a random seed, even though `seed` or `kwargs` appear in the signature. " | |
f"This should never happen, please report this issue. The error was: {e}" | |
) | |
seed_param = signature.parameters.get("seed") | |
# Check the default value is None | |
if seed_param is not None and seed_param.default is not None: | |
logger.warn( | |
"The default seed argument in reset should be `None`, otherwise the environment will by default always be deterministic. " | |
f"Actual default: {seed_param.default}" | |
) | |
else: | |
raise gym.error.Error( | |
"The `reset` method does not provide a `seed` or `**kwargs` keyword argument." | |
) | |
def check_reset_options(env: gym.Env): | |
"""Check that the environment can be reset with options. | |
Args: | |
env: The environment to check | |
Raises: | |
AssertionError: The environment cannot be reset with options, | |
even though `options` or `kwargs` appear in the signature. | |
""" | |
signature = inspect.signature(env.reset) | |
if "options" in signature.parameters or ( | |
"kwargs" in signature.parameters | |
and signature.parameters["kwargs"].kind is inspect.Parameter.VAR_KEYWORD | |
): | |
try: | |
env.reset(options={}) | |
except TypeError as e: | |
raise AssertionError( | |
"The environment cannot be reset with options, even though `options` or `**kwargs` appear in the signature. " | |
f"This should never happen, please report this issue. The error was: {e}" | |
) | |
else: | |
raise gym.error.Error( | |
"The `reset` method does not provide an `options` or `**kwargs` keyword argument." | |
) | |
def check_reset_return_info_deprecation(env: gym.Env): | |
"""Makes sure support for deprecated `return_info` argument is dropped. | |
Args: | |
env: The environment to check | |
Raises: | |
UserWarning | |
""" | |
signature = inspect.signature(env.reset) | |
if "return_info" in signature.parameters: | |
logger.warn( | |
"`return_info` is deprecated as an optional argument to `reset`. `reset`" | |
"should now always return `obs, info` where `obs` is an observation, and `info` is a dictionary" | |
"containing additional information." | |
) | |
def check_seed_deprecation(env: gym.Env): | |
"""Makes sure support for deprecated function `seed` is dropped. | |
Args: | |
env: The environment to check | |
Raises: | |
UserWarning | |
""" | |
seed_fn = getattr(env, "seed", None) | |
if callable(seed_fn): | |
logger.warn( | |
"Official support for the `seed` function is dropped. " | |
"Standard practice is to reset gym environments using `env.reset(seed=<desired seed>)`" | |
) | |
def check_reset_return_type(env: gym.Env): | |
"""Checks that :meth:`reset` correctly returns a tuple of the form `(obs , info)`. | |
Args: | |
env: The environment to check | |
Raises: | |
AssertionError depending on spec violation | |
""" | |
result = env.reset() | |
assert isinstance( | |
result, tuple | |
), f"The result returned by `env.reset()` was not a tuple of the form `(obs, info)`, where `obs` is a observation and `info` is a dictionary containing additional information. Actual type: `{type(result)}`" | |
assert ( | |
len(result) == 2 | |
), f"Calling the reset method did not return a 2-tuple, actual length: {len(result)}" | |
obs, info = result | |
assert ( | |
obs in env.observation_space | |
), "The first element returned by `env.reset()` is not within the observation space." | |
assert isinstance( | |
info, dict | |
), f"The second element returned by `env.reset()` was not a dictionary, actual type: {type(info)}" | |
def check_space_limit(space, space_type: str): | |
"""Check the space limit for only the Box space as a test that only runs as part of `check_env`.""" | |
if isinstance(space, spaces.Box): | |
if np.any(np.equal(space.low, -np.inf)): | |
logger.warn( | |
f"A Box {space_type} space minimum value is -infinity. This is probably too low." | |
) | |
if np.any(np.equal(space.high, np.inf)): | |
logger.warn( | |
f"A Box {space_type} space maximum value is -infinity. This is probably too high." | |
) | |
# Check that the Box space is normalized | |
if space_type == "action": | |
if len(space.shape) == 1: # for vector boxes | |
if ( | |
np.any( | |
np.logical_and( | |
space.low != np.zeros_like(space.low), | |
np.abs(space.low) != np.abs(space.high), | |
) | |
) | |
or np.any(space.low < -1) | |
or np.any(space.high > 1) | |
): | |
# todo - Add to gymlibrary.ml? | |
logger.warn( | |
"For Box action spaces, we recommend using a symmetric and normalized space (range=[-1, 1] or [0, 1]). " | |
"See https://stable-baselines3.readthedocs.io/en/master/guide/rl_tips.html for more information." | |
) | |
elif isinstance(space, spaces.Tuple): | |
for subspace in space.spaces: | |
check_space_limit(subspace, space_type) | |
elif isinstance(space, spaces.Dict): | |
for subspace in space.values(): | |
check_space_limit(subspace, space_type) | |
def check_env(env: gym.Env, warn: bool = None, skip_render_check: bool = False): | |
"""Check that an environment follows Gym API. | |
This is an invasive function that calls the environment's reset and step. | |
This is particularly useful when using a custom environment. | |
Please take a look at https://www.gymlibrary.dev/content/environment_creation/ | |
for more information about the API. | |
Args: | |
env: The Gym environment that will be checked | |
warn: Ignored | |
skip_render_check: Whether to skip the checks for the render method. True by default (useful for the CI) | |
""" | |
if warn is not None: | |
logger.warn("`check_env(warn=...)` parameter is now ignored.") | |
assert isinstance( | |
env, gym.Env | |
), "The environment must inherit from the gym.Env class. See https://www.gymlibrary.dev/content/environment_creation/ for more info." | |
if env.unwrapped is not env: | |
logger.warn( | |
f"The environment ({env}) is different from the unwrapped version ({env.unwrapped}). This could effect the environment checker as the environment most likely has a wrapper applied to it. We recommend using the raw environment for `check_env` using `env.unwrapped`." | |
) | |
# ============= Check the spaces (observation and action) ================ | |
assert hasattr( | |
env, "action_space" | |
), "The environment must specify an action space. See https://www.gymlibrary.dev/content/environment_creation/ for more info." | |
check_action_space(env.action_space) | |
check_space_limit(env.action_space, "action") | |
assert hasattr( | |
env, "observation_space" | |
), "The environment must specify an observation space. See https://www.gymlibrary.dev/content/environment_creation/ for more info." | |
check_observation_space(env.observation_space) | |
check_space_limit(env.observation_space, "observation") | |
# ==== Check the reset method ==== | |
check_seed_deprecation(env) | |
check_reset_return_info_deprecation(env) | |
check_reset_return_type(env) | |
check_reset_seed(env) | |
check_reset_options(env) | |
# ============ Check the returned values =============== | |
env_reset_passive_checker(env) | |
env_step_passive_checker(env, env.action_space.sample()) | |
# ==== Check the render method and the declared render modes ==== | |
if not skip_render_check: | |
if env.render_mode is not None: | |
env_render_passive_checker(env) | |
# todo: recreate the environment with a different render_mode for check that each work | |