Add utils to handle all known space types

fancy_rl/utils.py

@@ -0,0 +1,53 @@
+try:
+    import gym
+    from gym.spaces import Discrete as GymDiscrete, MultiDiscrete as GymMultiDiscrete, MultiBinary as GymMultiBinary, Box as GymBox
+except ImportError:
+    gym = None
+
+import gymnasium
+from gymnasium.spaces import Discrete as GymnasiumDiscrete, MultiDiscrete as GymnasiumMultiDiscrete, MultiBinary as GymnasiumMultiBinary, Box as GymnasiumBox
+from torchrl.data.tensor_specs import (
+    DiscreteTensorSpec, OneHotDiscreteTensorSpec, MultiDiscreteTensorSpec,
+    BinaryDiscreteTensorSpec, BoundedTensorSpec, UnboundedContinuousTensorSpec
+)
+
+def is_discrete_space(action_space):
+    discrete_types = (
+        GymDiscrete, GymMultiDiscrete, GymMultiBinary,
+        GymnasiumDiscrete, GymnasiumMultiDiscrete, GymnasiumMultiBinary,
+        DiscreteTensorSpec, OneHotDiscreteTensorSpec, MultiDiscreteTensorSpec, BinaryDiscreteTensorSpec
+    )
+    continuous_types = (
+        GymBox, GymnasiumBox, BoundedTensorSpec, UnboundedContinuousTensorSpec
+    )
+    
+    if isinstance(action_space, discrete_types):
+        return True
+    elif isinstance(action_space, continuous_types):
+        return False
+    else:
+        raise ValueError(f"Unsupported action space type: {type(action_space)}")
+
+def get_space_shape(action_space):
+    if gym is not None:
+        discrete_types = (GymDiscrete, GymMultiDiscrete, GymMultiBinary)
+        continuous_types = (GymBox,)
+    else:
+        discrete_types = ()
+        continuous_types = ()
+
+    discrete_types += (GymnasiumDiscrete, GymnasiumMultiDiscrete, GymnasiumMultiBinary,
+                       DiscreteTensorSpec, OneHotDiscreteTensorSpec, MultiDiscreteTensorSpec, BinaryDiscreteTensorSpec)
+    continuous_types += (GymnasiumBox, BoundedTensorSpec, UnboundedContinuousTensorSpec)
+
+    if isinstance(action_space, discrete_types):
+        if isinstance(action_space, (GymDiscrete, GymnasiumDiscrete, DiscreteTensorSpec, OneHotDiscreteTensorSpec)):
+            return (action_space.n,)
+        elif isinstance(action_space, (GymMultiDiscrete, GymnasiumMultiDiscrete, MultiDiscreteTensorSpec)):
+            return (sum(action_space.nvec),)
+        elif isinstance(action_space, (GymMultiBinary, GymnasiumMultiBinary, BinaryDiscreteTensorSpec)):
+            return (action_space.n,)
+    elif isinstance(action_space, continuous_types):
+        return action_space.shape
+    
+    raise ValueError(f"Unsupported action space type: {type(action_space)}")