Remove unnecessary printing from tests

Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/19606

Differential Revision: D15046583

Pulled By: ezyang

fbshipit-source-id: ea9bb691d23855e7eddbabe68bf112a726641ba4

test/test_torch.py

@@ -2691,8 +2691,6 @@ class _TestTorchMixin(object):
         zero_point = 2
         qr = r.quantize_linear(scale, zero_point)
         rqr = qr.dequantize()
-        print(r.numpy())
-        print(rqr.numpy())
         self.assertTrue(np.allclose(r.numpy(), rqr.numpy(), atol=2 / scale))
 
     def test_qtensor_creation(self):
@@ -2701,12 +2699,7 @@ class _TestTorchMixin(object):
         val = 100
         numel = 10
         q = torch._empty_affine_quantized(numel, dtype=torch.qint8, scale=scale, zero_point=zero_point)
-        # for i in range(numel):
-        #     # wait for th_fill
-        #     q[i] = val
-        # r = q.dequantize()
-        # for i in range(numel):
-        #     self.assertEqual(r[i], (val - zero_point) * scale)
+        # TODO: check dequantized values?
 
     @unittest.skipIf(torch.cuda.device_count() < 2, 'fewer than 2 GPUs detected')
     def test_device_guard(self):

test/test_utils.py

@@ -6,6 +6,7 @@ import shutil
 import random
 import tempfile
 import unittest
+import contextlib
 import torch
 import torch.nn as nn
 import torch.utils.data
@@ -492,11 +493,26 @@ class TestONNXUtils(TestCase):
         try_check_onnx_broadcast(dims1, dims2, True, False)
 
 
+# Errors will still be raised and reported
+@contextlib.contextmanager
+def suppress_stderr():
+    original = sys.stderr
+    sys.stderr = open(os.devnull, 'w')
+    yield
+    sys.stderr = original
+
+
 class TestHub(TestCase):
     @classmethod
     @skipIfNoTorchVision
     def setUpClass(cls):
-        cls.resnet18_pretrained = models.__dict__['resnet18'](pretrained=True).state_dict()
+        # The current torchvision code does not provide a way to disable tqdm
+        # progress bar, leading this download printing a huge number of lines
+        # in CI.
+        # TODO: remove this context manager when torchvision provides a way.
+        #       See pytorch/torchvision#862
+        with suppress_stderr():
+            cls.resnet18_pretrained = models.__dict__['resnet18'](pretrained=True).state_dict()
 
     @skipIfNoTorchVision
     def test_load_from_github(self):