Implemented ReseedWrapper to control seeding of environments.

gym_minigrid/wrappers.py

@@ -7,6 +7,28 @@ import gym
 from gym import error, spaces, utils
 from .minigrid import OBJECT_TO_IDX, COLOR_TO_IDX
 
+class ReseedWrapper(gym.core.Wrapper):
+    """
+    Wrapper to always regenerate an environment with the same set of seeds.
+    This can be used to force an environment to always keep the same
+    configuration when reset.
+    """
+
+    def __init__(self, env, seeds=[0], seed_idx=0):
+        self.seeds = list(seeds)
+        self.seed_idx = seed_idx
+        super().__init__(env)
+
+    def reset(self, **kwargs):
+        seed = self.seeds[self.seed_idx]
+        self.seed_idx = (self.seed_idx + 1) % len(self.seeds)
+        self.env.seed(seed)
+        return self.env.reset(**kwargs)
+
+    def step(self, action):
+        obs, reward, done, info = self.env.step(action)
+        return obs, reward, done, info
+
 class ActionBonus(gym.core.Wrapper):
     """
     Wrapper which adds an exploration bonus.

run_tests.py

@@ -71,6 +71,13 @@ for env_name in env_list:
     env.close()
 
     env = gym.make(env_name)
+    env = ReseedWrapper(env)
+    for _ in range(10):
+        env.reset()
+        env.step(0)
+        env.close()
+
+    env = gym.make(env_name)
     env = ImgObsWrapper(env)
     env.reset()
     env.step(0)