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   "source": [
    "[![Open in Binder](https://mybinder.org/badge_logo.svg)](https://mybinder.org/v2/gh/justmarkham/scikit-learn-tips/master?filepath=notebooks%2F45_feature_interactions.ipynb)\n",
    "\n",
    "[![Open in Colab](https://colab.research.google.com/assets/colab-badge.svg)](https://colab.research.google.com/github/justmarkham/scikit-learn-tips/blob/master/notebooks/45_feature_interactions.ipynb)\n",
    "\n",
    "# 🤖⚡ scikit-learn tip #45 ([video](https://www.youtube.com/watch?v=unP3rCfzROk&list=PL5-da3qGB5ID7YYAqireYEew2mWVvgmj6&index=45))\n",
    "\n",
    "Want to include \"feature interactions\" in your model? Use PolynomialFeatures!\n",
    "\n",
    "See example 👇\n",
    "\n",
    "P.S. This is impractical if you have lots of features, and unnecessary if you're using a tree-based model."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [],
   "source": [
    "import pandas as pd\n",
    "X = pd.DataFrame({'A':[1, 2, 3], 'B':[4, 4, 4], 'C':[0, 10, 100]})"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [],
   "source": [
    "from sklearn.preprocessing import PolynomialFeatures\n",
    "poly = PolynomialFeatures(include_bias=False, interaction_only=True)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [
    {
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       "   A  B    C\n",
       "0  1  4    0\n",
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       "2  3  4  100"
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     "execution_count": 3,
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   "source": [
    "X"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([[  1.,   4.,   0.,   4.,   0.,   0.],\n",
       "       [  2.,   4.,  10.,   8.,  20.,  40.],\n",
       "       [  3.,   4., 100.,  12., 300., 400.]])"
      ]
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     "execution_count": 4,
     "metadata": {},
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   "source": [
    "# Output columns: A, B, C, A*B, A*C, B*C\n",
    "poly.fit_transform(X)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Want more tips? [View all tips on GitHub](https://github.com/justmarkham/scikit-learn-tips) or [Sign up to receive 2 tips by email every week](https://scikit-learn.tips) 💌\n",
    "\n",
    "© 2020 [Data School](https://www.dataschool.io). All rights reserved."
   ]
  }
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