Fix __getattr__ warning (#676)

Author: pseudo-rnd-thoughts

Diff for: gymnasium/__init__.py

@@ -51,7 +51,7 @@
     "error",
     "logger",
 ]
-__version__ = "0.29.0"
+__version__ = "0.29.1"
 
 
 # Initializing pygame initializes audio connections through SDL. SDL uses alsa by default on all Linux systems

Diff for: gymnasium/core.py

@@ -13,6 +13,20 @@
 if TYPE_CHECKING:
     from gymnasium.envs.registration import EnvSpec, WrapperSpec
 
+
+__all__ = [
+    "Env",
+    "Wrapper",
+    "ObservationWrapper",
+    "RewardWrapper",
+    "ActionWrapper",
+    "ObsType",
+    "ActType",
+    "RenderFrame",
+    "WrapperObsType",
+    "WrapperActType",
+]
+
 ObsType = TypeVar("ObsType")
 ActType = TypeVar("ActType")
 RenderFrame = TypeVar("RenderFrame")
@@ -296,7 +310,7 @@ def __getattr__(self, name: str) -> Any:
             raise AttributeError(f"accessing private attribute '{name}' is prohibited")
         logger.warn(
             f"env.{name} to get variables from other wrappers is deprecated and will be removed in v1.0, "
-            f"to get this variable you can do `env.unwrapped.{name}` for environment variables or `env.get_attr('{name}')` that will search the reminding wrappers."
+            f"to get this variable you can do `env.unwrapped.{name}` for environment variables or `env.get_wrapper_attr('{name}')` that will search the reminding wrappers."
         )
         return getattr(self.env, name)
 
@@ -309,7 +323,7 @@ def get_wrapper_attr(self, name: str) -> Any:
         Returns:
             The variable with name in wrapper or lower environments
         """
-        if hasattr(self, name):
+        if name in self.__dir__():  # todo change in v1.0.0 to `hasattr`
             return getattr(self, name)
         else:
             try:

Diff for: gymnasium/vector/vector_env.py

@@ -5,6 +5,7 @@
 from numpy.typing import NDArray
 
 import gymnasium as gym
+from gymnasium import logger
 from gymnasium.vector.utils.spaces import batch_space
 
 
@@ -385,6 +386,10 @@ def set_attr(self, name, values):
     def __getattr__(self, name):
         if name.startswith("_"):
             raise AttributeError(f"attempted to get missing private attribute '{name}'")
+        logger.warn(
+            f"env.{name} to get variables from other wrappers is deprecated and will be removed in v1.0, "
+            f"to get this variable you can do `env.unwrapped.{name}` for environment variables."
+        )
         return getattr(self.env, name)
 
     @property

Diff for: pyproject.toml

@@ -39,8 +39,8 @@ accept-rom-license = ["autorom[accept-rom-license] ~=0.4.2"]
 box2d = ["box2d-py ==2.3.5", "pygame >=2.1.3", "swig ==4.*"]
 classic-control = ["pygame >=2.1.3"]
 classic_control = ["pygame >=2.1.3"]  # kept for backward compatibility
-mujoco-py = ["mujoco-py >=2.1,<2.2"]
-mujoco_py = ["mujoco-py >=2.1,<2.2"]       # kept for backward compatibility
+mujoco-py = ["mujoco-py >=2.1,<2.2", "cython<3"]
+mujoco_py = ["mujoco-py >=2.1,<2.2", "cython<3"]       # kept for backward compatibility
 mujoco = ["mujoco >=2.3.3", "imageio >=2.14.1"]
 toy-text = ["pygame >=2.1.3"]
 toy_text = ["pygame >=2.1.3"]         # kept for backward compatibility
@@ -65,6 +65,7 @@ all = [
     "pygame >=2.1.3",
     # mujoco-py
     "mujoco-py >=2.1,<2.2",
+    "cython<3",
     # mujoco
     "mujoco >=2.3.3",
     "imageio >=2.14.1",

Diff for: tests/test_core.py

@@ -1,10 +1,12 @@
 """Checks that the core Gymnasium API is implemented as expected."""
 import re
+import warnings
 from typing import Any, Dict, Optional, SupportsFloat, Tuple
 
 import numpy as np
 import pytest
 
+import gymnasium as gym
 from gymnasium import Env, ObservationWrapper, RewardWrapper, Wrapper, spaces
 from gymnasium.core import (
     ActionWrapper,
@@ -326,3 +328,22 @@ def test_wrapper_types():
     action_env = ExampleActionWrapper(env)
     obs, _, _, _, _ = action_env.step(0)
     assert obs == np.array([1])
+
+
+def test_get_wrapper_attr():
+    env = gym.make("CartPole-v1")
+
+    with warnings.catch_warnings(record=True) as caught_warnings:
+        gravity = env.get_wrapper_attr("gravity")
+
+    assert gravity == env.unwrapped.gravity
+    assert len(caught_warnings) == 0
+
+    with pytest.warns(
+        UserWarning,
+        match=re.escape(
+            "env.gravity to get variables from other wrappers is deprecated and will be removed in v1.0, to get this variable you can do `env.unwrapped.gravity` for environment variables or `env.get_wrapper_attr('gravity')` that will search the reminding wrappers."
+        ),
+    ):
+        gravity = env.gravity
+        assert gravity == env.unwrapped.gravity