Bugfix to gym version comparison, now uses package "packaging" for this.

pfrl/wrappers/atari_wrappers.py

@@ -7,6 +7,7 @@
 import gym
 import numpy as np
 from gym import spaces
+from packaging import version
 
 import pfrl
 
@@ -37,7 +38,7 @@ def reset(self, **kwargs):
         if self.override_num_noops is not None:
             noops = self.override_num_noops
         else:
-            if gym.__version__ >= "0.24.0":
+            if version.parse(gym.__version__) >= version.parse("0.24.0"):
                 noops = self.unwrapped.np_random.integers(1, self.noop_max + 1)
             else:
                 noops = self.unwrapped.np_random.randint(1, self.noop_max + 1)