Removed file descriptor name typo

examples/A3C-Gym/train-atari.py

@@ -155,7 +155,7 @@ class MySimulatorMaster(SimulatorMaster, Callback):
         self.fd = open('/kaggle/working/data_file', 'w')
 
     def __del__(self):
-        self.f.close()
+        self.fd.close()
 
     def _setup_graph(self):
         # Create predictors on the available predictor GPUs.
@@ -199,7 +199,7 @@ class MySimulatorMaster(SimulatorMaster, Callback):
             client.memory[-1].reward = reward
             if isOver:
                 # should clear client's memory and put to queue
-                self.f.write(str(self.reward) + '\n')
+                self.fd.write(str(self.reward) + '\n')
                 self.reward = 0
                 self._parse_memory(0, client, True)
             else: