Add py2 compatible imports

samples/core/tutorials/keras/basic_regression.ipynb

@@ -402,7 +402,7 @@
       },
       "cell_type": "code",
       "source": [
-        "from __future__ import print_function # python2 print compatibility",
+        "from __future__ import absolute_import, division, print_function\n",
         "\n",
         "# Display training progress by printing a single dot for each completed epoch\n",
         "class PrintDot(keras.callbacks.Callback):\n",