Revert "Fix FashionMNIST loading MNIST" (#646)

* Revert "move area calculation out of loop (#641)"

This reverts commit 62cbf0bf.

* Revert "Fix FashionMNIST loading MNIST (#640)"

This reverts commit 36215690.

test/test_datasets.py

-import torch
-from torchvision.datasets import MNIST, FashionMNIST
-import unittest
-import tempfile
-import shutil
-import os
-
-
-class Tester(unittest.TestCase):
-    def setUp(self):
-        self.test_dir = tempfile.mkdtemp()
-
-    def tearDown(self):
-        shutil.rmtree(self.test_dir)
-
-    def test_fashion_mnist_doesnt_load_mnist(self):
-        MNIST(root=self.test_dir, download=True)
-        FashionMNIST(root=self.test_dir, download=True)
-
-
-if __name__ == '__main__':
-    unittest.main()

torchvision/datasets/mnist.py

@@ -7,7 +7,6 @@ import gzip
 import numpy as np
 import torch
 import codecs
-import hashlib
 from .utils import download_url, makedir_exist_ok
 
 
@@ -27,25 +26,14 @@ class MNIST(data.Dataset):
         target_transform (callable, optional): A function/transform that takes in the
             target and transforms it.
     """
-
     urls = [
         'http://yann.lecun.com/exdb/mnist/train-images-idx3-ubyte.gz',
         'http://yann.lecun.com/exdb/mnist/train-labels-idx1-ubyte.gz',
         'http://yann.lecun.com/exdb/mnist/t10k-images-idx3-ubyte.gz',
         'http://yann.lecun.com/exdb/mnist/t10k-labels-idx1-ubyte.gz',
     ]
-
-    md5s = {
-        't10k-images-idx3-ubyte.gz': '9fb629c4189551a2d022fa330f9573f3',
-        't10k-labels-idx1-ubyte.gz': 'ec29112dd5afa0611ce80d1b7f02629c',
-        'train-images-idx3-ubyte.gz': 'f68b3c2dcbeaaa9fbdd348bbdeb94873',
-        'train-labels-idx1-ubyte.gz': 'd53e105ee54ea40749a09fcbcd1e9432',
-    }
-
-    raw_folder = 'raw'
-    processed_folder = 'processed'
-    training_file = 'mnist-training.pt'
-    test_file = 'mnist-test.pt'
+    training_file = 'training.pt'
+    test_file = 'test.pt'
     classes = ['0 - zero', '1 - one', '2 - two', '3 - three', '4 - four',
                '5 - five', '6 - six', '7 - seven', '8 - eight', '9 - nine']
 
@@ -62,22 +50,11 @@ class MNIST(data.Dataset):
             raise RuntimeError('Dataset not found.' +
                                ' You can use download=True to download it')
 
-        def load_data(filename):
-            loaded_data = torch.load(
-                os.path.join(self.root, self.processed_folder, filename))
-            if len(loaded_data) == 2:
-                return loaded_data
-            else:
-                clsname, data, labels = loaded_data
-                if clsname != type(self).__name__:
-                    raise RuntimeError("Expected {} data but found {}"
-                                       .format(type(self).__name__, clsname, ))
-                return data, labels
-
         if self.train:
-            self.train_data, self.train_labels = load_data(self.training_file)
+            data_file = self.training_file
         else:
-            self.train_data, self.train_labels = load_data(self.test_file)
+            data_file = self.test_file
+        self.data, self.targets = torch.load(os.path.join(self.processed_folder, data_file))
 
     def __getitem__(self, index):
         """
@@ -87,10 +64,7 @@ class MNIST(data.Dataset):
         Returns:
             tuple: (image, target) where target is index of the target class.
         """
-        if self.train:
-            img, target = self.train_data[index], self.train_labels[index]
-        else:
-            img, target = self.test_data[index], self.test_labels[index]
+        img, target = self.data[index], int(self.targets[index])
 
         # doing this so that it is consistent with all other datasets
         # to return a PIL Image
@@ -134,8 +108,6 @@ class MNIST(data.Dataset):
 
     def download(self):
         """Download the MNIST data if it doesn't exist in processed_folder already."""
-        from six.moves import urllib
-        import gzip
 
         if self._check_exists():
             return
@@ -147,21 +119,19 @@ class MNIST(data.Dataset):
         for url in self.urls:
             filename = url.rpartition('/')[2]
             file_path = os.path.join(self.raw_folder, filename)
-            download_url(url, root=self.raw_folder, filename=filename, md5=self.md5s[filename])
+            download_url(url, root=self.raw_folder, filename=filename, md5=None)
             self.extract_gzip(gzip_path=file_path, remove_finished=True)
 
         # process and save as torch files
         print('Processing...')
 
         training_set = (
-            type(self).__name__,
-            read_image_file(os.path.join(self.root, self.raw_folder, 'train-images-idx3-ubyte')),
-            read_label_file(os.path.join(self.root, self.raw_folder, 'train-labels-idx1-ubyte'))
+            read_image_file(os.path.join(self.raw_folder, 'train-images-idx3-ubyte')),
+            read_label_file(os.path.join(self.raw_folder, 'train-labels-idx1-ubyte'))
         )
         test_set = (
-            type(self).__name__,
-            read_image_file(os.path.join(self.root, self.raw_folder, 't10k-images-idx3-ubyte')),
-            read_label_file(os.path.join(self.root, self.raw_folder, 't10k-labels-idx1-ubyte'))
+            read_image_file(os.path.join(self.raw_folder, 't10k-images-idx3-ubyte')),
+            read_label_file(os.path.join(self.raw_folder, 't10k-labels-idx1-ubyte'))
         )
         with open(os.path.join(self.processed_folder, self.training_file), 'wb') as f:
             torch.save(training_set, f)
@@ -199,22 +169,14 @@ class FashionMNIST(MNIST):
         target_transform (callable, optional): A function/transform that takes in the
             target and transforms it.
     """
-    training_file = 'fashion-mnist-training.pt'
-    test_file = 'fashion-mnist-test.pt'
-
     urls = [
         'http://fashion-mnist.s3-website.eu-central-1.amazonaws.com/train-images-idx3-ubyte.gz',
         'http://fashion-mnist.s3-website.eu-central-1.amazonaws.com/train-labels-idx1-ubyte.gz',
         'http://fashion-mnist.s3-website.eu-central-1.amazonaws.com/t10k-images-idx3-ubyte.gz',
         'http://fashion-mnist.s3-website.eu-central-1.amazonaws.com/t10k-labels-idx1-ubyte.gz',
     ]
-
-    md5s = {
-        't10k-images-idx3-ubyte.gz': 'bef4ecab320f06d8554ea6380940ec79',
-        't10k-labels-idx1-ubyte.gz': 'bb300cfdad3c16e7a12a480ee83cd310',
-        'train-images-idx3-ubyte.gz': '8d4fb7e6c68d591d4c3dfef9ec88bf0d',
-        'train-labels-idx1-ubyte.gz': '25c81989df183df01b3e8a0aad5dffbe',
-    }
+    classes = ['T-shirt/top', 'Trouser', 'Pullover', 'Dress', 'Coat', 'Sandal',
+               'Shirt', 'Sneaker', 'Bag', 'Ankle boot']
 
 
 class EMNIST(MNIST):