diff --git a/work_in_progress/extra_autodiff.ipynb b/work_in_progress/extra_autodiff.ipynb
index dbd3088..aef8d43 100644
--- a/work_in_progress/extra_autodiff.ipynb
+++ b/work_in_progress/extra_autodiff.ipynb
@@ -21,23 +21,6 @@
     "# Setup"
    ]
   },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "First, let's make sure this notebook works well in both python 2 and 3:"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 1,
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "# To support both python 2 and python 3\n",
-    "from __future__ import absolute_import, division, print_function, unicode_literals"
-   ]
-  },
   {
    "cell_type": "markdown",
    "metadata": {},
diff --git a/work_in_progress/extra_capsnets-cn.ipynb b/work_in_progress/extra_capsnets-cn.ipynb
index f674ebd..32b4753 100644
--- a/work_in_progress/extra_capsnets-cn.ipynb
+++ b/work_in_progress/extra_capsnets-cn.ipynb
@@ -68,22 +68,6 @@
     "# Imports"
    ]
   },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "同时支持 Python 2 和 Python 3："
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 78,
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "from __future__ import division, print_function, unicode_literals"
-   ]
-  },
   {
    "cell_type": "markdown",
    "metadata": {},
diff --git a/work_in_progress/extra_capsnets.ipynb b/work_in_progress/extra_capsnets.ipynb
index 1569b4a..b951392 100644
--- a/work_in_progress/extra_capsnets.ipynb
+++ b/work_in_progress/extra_capsnets.ipynb
@@ -68,22 +68,6 @@
     "# Imports"
    ]
   },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "To support both Python 2 and Python 3:"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 3,
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "from __future__ import division, print_function, unicode_literals"
-   ]
-  },
   {
    "cell_type": "markdown",
    "metadata": {},
diff --git a/work_in_progress/extra_tensorflow_reproducibility.ipynb b/work_in_progress/extra_tensorflow_reproducibility.ipynb
index 436a334..99f06ac 100644
--- a/work_in_progress/extra_tensorflow_reproducibility.ipynb
+++ b/work_in_progress/extra_tensorflow_reproducibility.ipynb
@@ -13,8 +13,6 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "from __future__ import division, print_function, unicode_literals\n",
-    "\n",
     "import numpy as np\n",
     "import tensorflow as tf\n",
     "from tensorflow import keras"