Fix VOC on Windows (#1641)

torchvision/datasets/voc.py

@@ -17,37 +17,37 @@ DATASET_YEAR_DICT = {
         'url': 'http://host.robots.ox.ac.uk/pascal/VOC/voc2012/VOCtrainval_11-May-2012.tar',
         'filename': 'VOCtrainval_11-May-2012.tar',
         'md5': '6cd6e144f989b92b3379bac3b3de84fd',
-        'base_dir': 'VOCdevkit/VOC2012'
+        'base_dir': os.path.join('VOCdevkit', 'VOC2012')
     },
     '2011': {
         'url': 'http://host.robots.ox.ac.uk/pascal/VOC/voc2011/VOCtrainval_25-May-2011.tar',
         'filename': 'VOCtrainval_25-May-2011.tar',
         'md5': '6c3384ef61512963050cb5d687e5bf1e',
-        'base_dir': 'TrainVal/VOCdevkit/VOC2011'
+        'base_dir': os.path.join('TrainVal', 'VOCdevkit', 'VOC2011')
     },
     '2010': {
         'url': 'http://host.robots.ox.ac.uk/pascal/VOC/voc2010/VOCtrainval_03-May-2010.tar',
         'filename': 'VOCtrainval_03-May-2010.tar',
         'md5': 'da459979d0c395079b5c75ee67908abb',
-        'base_dir': 'VOCdevkit/VOC2010'
+        'base_dir': os.path.join('VOCdevkit', 'VOC2010')
     },
     '2009': {
         'url': 'http://host.robots.ox.ac.uk/pascal/VOC/voc2009/VOCtrainval_11-May-2009.tar',
         'filename': 'VOCtrainval_11-May-2009.tar',
         'md5': '59065e4b188729180974ef6572f6a212',
-        'base_dir': 'VOCdevkit/VOC2009'
+        'base_dir': os.path.join('VOCdevkit', 'VOC2009')
     },
     '2008': {
         'url': 'http://host.robots.ox.ac.uk/pascal/VOC/voc2008/VOCtrainval_14-Jul-2008.tar',
         'filename': 'VOCtrainval_11-May-2012.tar',
         'md5': '2629fa636546599198acfcfbfcf1904a',
-        'base_dir': 'VOCdevkit/VOC2008'
+        'base_dir': os.path.join('VOCdevkit', 'VOC2008')
     },
     '2007': {
         'url': 'http://host.robots.ox.ac.uk/pascal/VOC/voc2007/VOCtrainval_06-Nov-2007.tar',
         'filename': 'VOCtrainval_06-Nov-2007.tar',
         'md5': 'c52e279531787c972589f7e41ab4ae64',
-        'base_dir': 'VOCdevkit/VOC2007'
+        'base_dir': os.path.join('VOCdevkit', 'VOC2007')
     }
 }