add yapf style and apply yapf to format all Python files

This recreates pull request #2192

examples/pybullet/gym/pybullet_envs/baselines/enjoy_kuka_grasping.py

@@ -2,7 +2,7 @@
 import os, inspect
 currentdir = os.path.dirname(os.path.abspath(inspect.getfile(inspect.currentframe())))
 parentdir = os.path.dirname(os.path.dirname(currentdir))
-os.sys.path.insert(0,parentdir)
+os.sys.path.insert(0, parentdir)
 
 import gym
 from pybullet_envs.bullet.kukaGymEnv import KukaGymEnv
@@ -11,22 +11,22 @@ from baselines import deepq
 
 
 def main():
-    
-    env = KukaGymEnv(renders=True, isDiscrete=True)
-    act = deepq.load("kuka_model.pkl")
-    print(act)
-    while True:
-        obs, done = env.reset(), False
-        print("===================================")        
-        print("obs")
-        print(obs)
-        episode_rew = 0
-        while not done:
-            env.render()
-            obs, rew, done, _ = env.step(act(obs[None])[0])
-            episode_rew += rew
-        print("Episode reward", episode_rew)
+
+  env = KukaGymEnv(renders=True, isDiscrete=True)
+  act = deepq.load("kuka_model.pkl")
+  print(act)
+  while True:
+    obs, done = env.reset(), False
+    print("===================================")
+    print("obs")
+    print(obs)
+    episode_rew = 0
+    while not done:
+      env.render()
+      obs, rew, done, _ = env.step(act(obs[None])[0])
+      episode_rew += rew
+    print("Episode reward", episode_rew)
 
 
 if __name__ == '__main__':
-    main()
+  main()