From 1d5ea34f6abd0b62ed89a8d5fa4cc14ed970cf67 Mon Sep 17 00:00:00 2001
From: Jonathan Chang <31893406+cccntu@users.noreply.github.com>
Date: Mon, 12 Oct 2020 04:45:12 -0700
Subject: [PATCH] Fix trainer callback (#7720)

Fix a bug that happends when subclassing Trainer and
overwriting evaluate() without calling prediciton_loop()
---
 src/transformers/trainer_callback.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/transformers/trainer_callback.py b/src/transformers/trainer_callback.py
index bc14d99f25..c3057f8825 100644
--- a/src/transformers/trainer_callback.py
+++ b/src/transformers/trainer_callback.py
@@ -443,7 +443,8 @@ class ProgressCallback(TrainerCallback):
 
     def on_evaluate(self, args, state, control, **kwargs):
         if state.is_local_process_zero:
-            self.prediction_bar.close()
+            if self.prediction_bar is not None:
+                self.prediction_bar.close()
             self.prediction_bar = None
 
     def on_log(self, args, state, control, logs=None, **kwargs):