Refactor FashionMNIST notebook to use next() for data iterator and …

…fix subplot division (#3322)

examples/notebooks/FashionMNIST.ipynb

@@ -605,7 +605,7 @@
         "classes = ['T-shirt/top','Trouser','Pullover','Dress','Coat','Sandal','Shirt','Sneaker','Bag','Ankle Boot']\n",
         "# creating iterator for iterating the dataset\n",
         "dataiter = iter(val_loader)\n",
-        "images, labels = dataiter.next()\n",
+        "images, labels = next(dataiter)\n",
         "images_arr = []\n",
         "labels_arr = []\n",
         "pred_arr = []\n",
@@ -621,7 +621,7 @@
         "# plotting the results\n",
         "fig = plt.figure(figsize=(25,4))\n",
         "for i in range(10):\n",
-        "    ax = fig.add_subplot(2, 20/2, i+1, xticks=[], yticks=[])\n",
+        "    ax = fig.add_subplot(2, 20//2, i+1, xticks=[], yticks=[])\n",
         "    ax.imshow(images_arr[i].resize_(1, 28, 28).numpy().squeeze())\n",
         "    ax.set_title(\"{} ({})\".format(classes[pred_arr[i]], classes[labels_arr[i]]),\n",
         "                 color=(\"green\" if pred_arr[i]==labels_arr[i] else \"red\"))"