Clear predict_progress_bar in ProgressBar.__getstate__ (#7608)

Co-authored-by: Yifu Wang <yifuwang@2012@gmail.com>
Co-authored-by: Justus Schock <12886177+justusschock@users.noreply.github.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Carlos Mocholi <carlossmocholi@gmail.com>

CHANGELOG.md

@@ -5,6 +5,14 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 
 
+
+
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+- Fixed `ProgressBar` pickling after calling `trainer.predict` ([#7608](https://github.com/PyTorchLightning/pytorch-lightning/pull/7608))
+
+
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+
 ## [1.3.2] - 2021-05-18
 
 ### Changed

pytorch_lightning/callbacks/progress.py

@@ -283,13 +283,15 @@ def __init__(self, refresh_rate: int = 1, process_position: int = 0):
         self.main_progress_bar = None
         self.val_progress_bar = None
         self.test_progress_bar = None
+        self.predict_progress_bar = None
 
     def __getstate__(self):
         # can't pickle the tqdm objects
         state = self.__dict__.copy()
         state['main_progress_bar'] = None
         state['val_progress_bar'] = None
         state['test_progress_bar'] = None
+        state['predict_progress_bar'] = None
         return state
 
     @property

tests/callbacks/test_progress_bar.py

@@ -12,6 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import os
+import pickle
 import sys
 from typing import Optional, Union
 from unittest import mock
@@ -482,3 +483,17 @@ def test_progress_bar_print_disabled(tqdm_write, mock_print, tmpdir):
         call("test_step"),
     ])
     tqdm_write.assert_not_called()
+
+
+def test_progress_bar_can_be_pickled():
+    bar = ProgressBar()
+    trainer = Trainer(fast_dev_run=True, callbacks=[bar], max_steps=1)
+    model = BoringModel()
+
+    pickle.dumps(bar)
+    trainer.fit(model)
+    pickle.dumps(bar)
+    trainer.test(model)
+    pickle.dumps(bar)
+    trainer.predict(model)
+    pickle.dumps(bar)