add file arg to tqdm utils / callbacks

Summary:
# Context
tqdm by default prints to stderr. This can be unintuitive location for the progress bar to appear
# This Diff
Adds `file` arg so users can pass `sys.stdout` in they want to print there instead

Reviewed By: gunchu

Differential Revision: D53718992

fbshipit-source-id: 8dce3a23880c60a1e6238916402a008108881581

tests/utils/test_tqdm.py

@@ -0,0 +1,50 @@
+#!/usr/bin/env python3
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the BSD-style license found in the
+# LICENSE file in the root directory of this source tree.
+
+import sys
+import unittest
+from io import StringIO
+from unittest.mock import MagicMock, patch
+
+from torchtnt.utils.tqdm import create_progress_bar
+
+
+class TQDMTest(unittest.TestCase):
+    @patch("sys.stdout", new_callable=StringIO)
+    @patch("sys.stderr", new_callable=StringIO)
+    def test_tqdm_file(self, mock_stderr: MagicMock, mock_stdout: MagicMock) -> None:
+        """
+        Test the file argument to create_progress_bar
+        """
+
+        create_progress_bar(
+            dataloader=["foo", "bar"],
+            desc="foo",
+            num_epochs_completed=0,
+            num_steps_completed=0,
+            max_steps=None,
+            max_steps_per_epoch=None,
+            file=None,
+        )
+        self.assertIn(
+            "foo 0:   0%|          | 0/2 [00:00<?, ?it/s]", mock_stderr.getvalue()
+        )
+        # ensure nothing written to stdout
+        self.assertEqual(mock_stdout.getvalue(), "")
+
+        create_progress_bar(
+            dataloader=["foo", "bar"],
+            desc="foo",
+            num_epochs_completed=0,
+            num_steps_completed=0,
+            max_steps=None,
+            max_steps_per_epoch=None,
+            file=sys.stdout,
+        )
+        self.assertIn(
+            "foo 0:   0%|          | 0/2 [00:00<?, ?it/s]", mock_stdout.getvalue()
+        )

torchtnt/framework/callbacks/tqdm_progress_bar.py

@@ -4,7 +4,8 @@
 # This source code is licensed under the BSD-style license found in the
 # LICENSE file in the root directory of this source tree.
 
-from typing import Optional
+import io
+from typing import Optional, TextIO, Union
 
 from pyre_extensions import none_throws
 
@@ -27,10 +28,16 @@ class TQDMProgressBar(Callback):
 
     Args:
         refresh_rate: Determines at which rate (in number of steps) the progress bars get updated.
+        file: specifies where to output the progress messages (default: sys.stderr)
     """
 
-    def __init__(self, refresh_rate: int = 1) -> None:
+    def __init__(
+        self,
+        refresh_rate: int = 1,
+        file: Optional[Union[TextIO, io.StringIO]] = None,
+    ) -> None:
         self._refresh_rate = refresh_rate
+        self._file = file
 
         self._train_progress_bar: Optional[tqdm] = None
         self._eval_progress_bar: Optional[tqdm] = None
@@ -46,6 +53,7 @@ def on_train_epoch_start(self, state: State, unit: TTrainUnit) -> None:
                 num_steps_completed=unit.train_progress.num_steps_completed_in_epoch,
                 max_steps=train_state.max_steps,
                 max_steps_per_epoch=train_state.max_steps_per_epoch,
+                file=self._file,
             )
 
     def on_train_step_end(self, state: State, unit: TTrainUnit) -> None:
@@ -76,6 +84,7 @@ def on_eval_epoch_start(self, state: State, unit: TEvalUnit) -> None:
                 num_steps_completed=unit.eval_progress.num_steps_completed_in_epoch,
                 max_steps=eval_state.max_steps,
                 max_steps_per_epoch=eval_state.max_steps_per_epoch,
+                file=self._file,
             )
 
     def on_eval_step_end(self, state: State, unit: TEvalUnit) -> None:
@@ -106,6 +115,7 @@ def on_predict_epoch_start(self, state: State, unit: TPredictUnit) -> None:
                 num_steps_completed=unit.predict_progress.num_steps_completed,
                 max_steps=predict_state.max_steps,
                 max_steps_per_epoch=predict_state.max_steps_per_epoch,
+                file=self._file,
             )
 
     def on_predict_step_end(self, state: State, unit: TPredictUnit) -> None:

torchtnt/utils/tqdm.py

@@ -5,8 +5,9 @@
 # This source code is licensed under the BSD-style license found in the
 # LICENSE file in the root directory of this source tree.
 
+import io
 import logging
-from typing import Iterable, Optional
+from typing import Iterable, Optional, TextIO, Union
 
 from torchtnt.utils.progress import estimated_steps_in_epoch
 from tqdm.auto import tqdm
@@ -22,6 +23,7 @@ def create_progress_bar(
     num_steps_completed: int,
     max_steps: Optional[int],
     max_steps_per_epoch: Optional[int],
+    file: Optional[Union[TextIO, io.StringIO]] = None,
 ) -> tqdm:
     """Constructs a :func:`tqdm` progress bar. The number of steps in an epoch is inferred from the dataloader, num_steps_completed, max_steps and max_steps_per_epoch.
 
@@ -32,6 +34,7 @@ def create_progress_bar(
         num_steps_completed: an integer for the number of steps completed so far in the loop.
         max_steps: an optional integer for the number of max steps in the loop.
         max_steps_per_epoch: an optional integer for the number of max steps per epoch.
+        file: specifies where to output the progress messages (default: sys.stderr)
     """
     current_epoch = num_epochs_completed
     total = estimated_steps_in_epoch(
@@ -45,6 +48,7 @@ def create_progress_bar(
         total=total,
         initial=num_steps_completed,
         bar_format="{l_bar}{bar}{r_bar}\n",
+        file=file,
     )