remove unused imports (#3740)

Co-authored-by: Vasilis Vryniotis <datumbox@users.noreply.github.com>

torchvision/datasets/hmdb51.py

 import glob
 import os
 
-from .utils import list_dir
 from .folder import find_classes, make_dataset
 from .video_utils import VideoClips
 from .vision import VisionDataset

torchvision/datasets/ucf101.py

 import os
 
-from .utils import list_dir
 from .folder import find_classes, make_dataset
 from .video_utils import VideoClips
 from .vision import VisionDataset

torchvision/datasets/voc.py

 import os
-import tarfile
 import collections
 from .vision import VisionDataset
 from xml.etree.ElementTree import Element as ET_Element

torchvision/io/_video_opt.py

@@ -26,7 +26,6 @@ try:
     if os.name == 'nt':
         # Load the video_reader extension using LoadLibraryExW
         import ctypes
-        import sys
 
         kernel32 = ctypes.WinDLL('kernel32.dll', use_last_error=True)
         with_load_library_flags = hasattr(kernel32, 'AddDllDirectory')

torchvision/io/image.py

@@ -22,7 +22,6 @@ try:
     if os.name == 'nt':
         # Load the image extension using LoadLibraryExW
         import ctypes
-        import sys
 
         kernel32 = ctypes.WinDLL('kernel32.dll', use_last_error=True)
         with_load_library_flags = hasattr(kernel32, 'AddDllDirectory')

torchvision/io/video.py

@@ -8,7 +8,6 @@ import numpy as np
 import torch
 
 from . import _video_opt
-from ._video_opt import VideoMetaData
 
 
 try:

torchvision/models/detection/faster_rcnn.py

-import torch
 from torch import nn
 import torch.nn.functional as F
 

torchvision/models/quantization/inception.py

 import warnings
-from collections import namedtuple
 
 import torch
 import torch.nn as nn

torchvision/models/quantization/resnet.py

@@ -2,8 +2,7 @@ import torch
 from torchvision.models.resnet import Bottleneck, BasicBlock, ResNet, model_urls
 import torch.nn as nn
 from torchvision.models.utils import load_state_dict_from_url
-from torch.quantization import QuantStub, DeQuantStub, fuse_modules
-from torch._jit_internal import Optional
+from torch.quantization import fuse_modules
 from .utils import _replace_relu, quantize_model
 
 __all__ = ['QuantizableResNet', 'resnet18', 'resnet50',