Use fixed version number.

docs/source/examples/Notebook/Importing Notebooks.ipynb

@@ -40,7 +40,7 @@
    "outputs": [],
    "source": [
     "from IPython import get_ipython\n",
-    "from nbformat import read, current_nbformat\n",
+    "from nbformat import read\n",
     "from IPython.core.interactiveshell import InteractiveShell"
    ]
   },
@@ -130,7 +130,7 @@
     "                                       \n",
     "        # load the notebook object\n",
     "        with io.open(path, 'r', encoding='utf-8') as f:\n",
-    "            nb = read(f, current_nbformat)\n",
+    "            nb = read(f, 4)\n",
     "        \n",
     "        \n",
     "        # create the module and add it to sys.modules\n",
@@ -327,7 +327,7 @@
     "def show_notebook(fname):\n",
     "    \"\"\"display a short summary of the cells of a notebook\"\"\"\n",
     "    with io.open(fname, 'r', encoding='utf-8') as f:\n",
-    "        nb = read(f, current_nbformat)\n",
+    "        nb = read(f, 4)\n",
     "    html = []\n",
     "    for cell in nb.cells:\n",
     "        html.append(\"<h4>%s cell</h4>\" % cell.cell_type)\n",