{
 "cells": [
  {
   "cell_type": "code",
   "execution_count": 1,
   "id": "spread-happiness",
   "metadata": {},
   "outputs": [],
   "source": [
    "%matplotlib inline\n",
    "%load_ext autoreload\n",
    "%autoreload 2\n",
    "\n",
    "import numpy as np\n",
    "import pandas as pd\n",
    "import matplotlib.pyplot as plt\n",
    "import seaborn as sns\n",
    "from IPython.display import Markdown, display, HTML\n",
    "\n",
    "# Fix the dying kernel problem (only a problem in some installations - you can remove it, if it works without it)\n",
    "import os\n",
    "os.environ['KMP_DUPLICATE_LIB_OK'] = 'True'"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "approximate-classic",
   "metadata": {},
   "source": [
    "# Numpy\n",
    "\n",
    "For a detailed reference check out: https://numpy.org/doc/stable/reference/arrays.indexing.html."
   ]
  },
  {
   "cell_type": "markdown",
   "id": "renewable-chase",
   "metadata": {},
   "source": [
    "## Creating numpy arrays"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "afraid-consortium",
   "metadata": {},
   "source": [
    "### Directly"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "id": "textile-mainland",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[[1. 2. 3.]\n",
      " [4. 5. 6.]\n",
      " [7. 8. 9.]]\n"
     ]
    }
   ],
   "source": [
    "a = np.array(\n",
    "    [[1.0, 2.0, 3.0], \n",
    "     [4.0, 5.0, 6.0], \n",
    "     [7.0, 8.0, 9.0]]\n",
    ")\n",
    "\n",
    "print(a)"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "floating-junior",
   "metadata": {},
   "source": [
    "### From a list"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "id": "reasonable-mistress",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[[1.0, 2.0, 3.0], [4.0, 5.0, 6.0], [7.0, 8.0, 9.0]]\n",
      "\n",
      "[[1. 2. 3.]\n",
      " [4. 5. 6.]\n",
      " [7. 8. 9.]]\n"
     ]
    }
   ],
   "source": [
    "a = [[1.0, 2.0, 3.0], \n",
    "     [4.0, 5.0, 6.0], \n",
    "     [7.0, 8.0, 9.0]]\n",
    "\n",
    "print(a)\n",
    "print()\n",
    "\n",
    "a = np.array(a)\n",
    "\n",
    "print(a)"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "incorrect-practitioner",
   "metadata": {},
   "source": [
    "### From a list comprehension"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "id": "straight-cooling",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[0, 1, 4, 9, 16, 25, 36, 49, 64, 81]\n",
      "\n",
      "[ 0  1  4  9 16 25 36 49 64 81]\n"
     ]
    }
   ],
   "source": [
    "a = [i**2 for i in range(10)]\n",
    "\n",
    "print(a)\n",
    "print()\n",
    "print(np.array(a))"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "suffering-myanmar",
   "metadata": {},
   "source": [
    "### Ready-made functions in numpy"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "id": "expensive-bowling",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "All zeros\n",
      "[[0. 0. 0. 0.]\n",
      " [0. 0. 0. 0.]\n",
      " [0. 0. 0. 0.]]\n",
      "\n",
      "All chosen value (variant 1)\n",
      "[[7. 7. 7. 7.]\n",
      " [7. 7. 7. 7.]\n",
      " [7. 7. 7. 7.]]\n",
      "\n",
      "All chosen value (variant 2)\n",
      "[[7. 7. 7. 7.]\n",
      " [7. 7. 7. 7.]\n",
      " [7. 7. 7. 7.]]\n",
      "\n",
      "Random integers\n",
      "[[7 5]\n",
      " [9 8]\n",
      " [6 3]]\n",
      "\n",
      "Random values from the normal distribution\n",
      "[[  3.88109518 -15.30896612]\n",
      " [  7.88779281   7.67458172]\n",
      " [ -9.81026963  -6.02098263]]\n"
     ]
    }
   ],
   "source": [
    "# All zeros\n",
    "a = np.zeros((3, 4))\n",
    "print(\"All zeros\")\n",
    "print(a)\n",
    "print()\n",
    "\n",
    "# All a chosen value\n",
    "a = np.full((3, 4), 7.0)\n",
    "print(\"All chosen value (variant 1)\")\n",
    "print(a)\n",
    "print()\n",
    "\n",
    "# or\n",
    "\n",
    "a = np.zeros((3, 4))\n",
    "a[:] = 7.0\n",
    "print(\"All chosen value (variant 2)\")\n",
    "print(a)\n",
    "print()\n",
    "\n",
    "# Random integers\n",
    "\n",
    "a = np.random.randint(low=0, high=10, size=(3, 2))\n",
    "print(\"Random integers\")\n",
    "print(a)\n",
    "print()\n",
    "\n",
    "# Random values from the normal distribution (Gaussian)\n",
    "\n",
    "print(\"Random values from the normal distribution\")\n",
    "a = np.random.normal(loc=0, scale=10, size=(3, 2))\n",
    "print(a)"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "aggressive-titanium",
   "metadata": {},
   "source": [
    "## Slicing numpy arrays"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "former-richardson",
   "metadata": {},
   "source": [
    "### Slicing in 1D\n",
    "\n",
    "To obtain only specific values from a numpy array one can use so called slicing. It has the form\n",
    "\n",
    "**arr[low:high:step]**\n",
    "\n",
    "where low is the lowest index to be retrieved, high is the lowest index not to be retrieved and step indicates that every step element will be taken."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "id": "desirable-documentary",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Original:  [0, 1, 4, 9, 16, 25, 36, 49, 64, 81]\n",
      "First 5 elements: [0, 1, 4, 9, 16]\n",
      "Elements from index 3 to index 5: [9, 16, 25]\n",
      "Last 3 elements (negative indexing): [49, 64, 81]\n",
      "Printed in reverse order: [81, 64, 49, 36, 25, 16, 9, 4, 1, 0]\n",
      "Every second element: [0, 4, 16, 36, 64]\n"
     ]
    }
   ],
   "source": [
    "a = [i**2 for i in range(10)]\n",
    "\n",
    "print(\"Original: \", a)\n",
    "print(\"First 5 elements:\", a[:5])\n",
    "print(\"Elements from index 3 to index 5:\", a[3:6])\n",
    "print(\"Last 3 elements (negative indexing):\", a[-3:])\n",
    "print(\"Printed in reverse order:\", a[::-1])\n",
    "print(\"Every second element:\", a[::2])"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "micro-explosion",
   "metadata": {},
   "source": [
    "### Slicing in 2D\n",
    "\n",
    "In two dimensions it works similarly, just the slicing is separate for every dimension."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 11,
   "id": "disciplinary-think",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Original: \n",
      "[[ 0  1  2  3  4]\n",
      " [ 5  6  7  8  9]\n",
      " [10 11 12 13 14]\n",
      " [15 16 17 18 19]\n",
      " [20 21 22 23 24]]\n",
      "\n",
      "First 2 elements of the first 3 row:\n",
      "[[ 0  1]\n",
      " [ 5  6]\n",
      " [10 11]]\n",
      "\n",
      "Middle 3 elements from the middle 3 rows:\n",
      "[[ 6  7  8]\n",
      " [11 12 13]\n",
      " [16 17 18]]\n",
      "\n",
      "Bottom-right 3 by 3 submatrix (negative indexing):\n",
      "[[12 13 14]\n",
      " [17 18 19]\n",
      " [22 23 24]]\n",
      "\n",
      "Reversed columns:\n",
      "[[ 4  3  2  1  0]\n",
      " [ 9  8  7  6  5]\n",
      " [14 13 12 11 10]\n",
      " [19 18 17 16 15]\n",
      " [24 23 22 21 20]]\n",
      "\n"
     ]
    }
   ],
   "source": [
    "a = np.array([i for i in range(25)]).reshape(5, 5)\n",
    "\n",
    "print(\"Original: \")\n",
    "print(a)\n",
    "print()\n",
    "print(\"First 2 elements of the first 3 row:\")\n",
    "print(a[:3, :2])\n",
    "print()\n",
    "print(\"Middle 3 elements from the middle 3 rows:\")\n",
    "print(a[1:4, 1:4])\n",
    "print()\n",
    "print(\"Bottom-right 3 by 3 submatrix (negative indexing):\")\n",
    "print(a[-3:, -3:])\n",
    "print()\n",
    "print(\"Reversed columns:\")\n",
    "print(a[:, ::-1])\n",
    "print()"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "removable-canyon",
   "metadata": {},
   "source": [
    "### Setting numpy array field values"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "id": "senior-serbia",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Original: \n",
      "[[ 0  1  2  3  4]\n",
      " [ 5  6  7  8  9]\n",
      " [10 11 12 13 14]\n",
      " [15 16 17 18 19]\n",
      " [20 21 22 23 24]]\n",
      "\n",
      "Middle values changed to 5\n",
      "[[ 0  1  2  3  4]\n",
      " [ 5  5  5  5  9]\n",
      " [10  5  5  5 14]\n",
      " [15  5  5  5 19]\n",
      " [20 21 22 23 24]]\n",
      "\n",
      "Second matrix\n",
      "[[ 0  0  2]\n",
      " [ 6 12 20]\n",
      " [30 42 56]]\n",
      "\n",
      "Second matrix substituted into the middle of the first matrix\n",
      "[[ 0  1  2  3  4]\n",
      " [ 5  0  0  2  9]\n",
      " [10  6 12 20 14]\n",
      " [15 30 42 56 19]\n",
      " [20 21 22 23 24]]\n"
     ]
    }
   ],
   "source": [
    "a = np.array([i for i in range(25)]).reshape(5, 5)\n",
    "\n",
    "print(\"Original: \")\n",
    "print(a)\n",
    "print()\n",
    "\n",
    "a[1:4, 1:4] = 5.0\n",
    "\n",
    "print(\"Middle values changed to 5\")\n",
    "print(a)\n",
    "print()\n",
    "\n",
    "b = np.array([i**2 - i for i in range(9)]).reshape(3, 3)\n",
    "\n",
    "print(\"Second matrix\")\n",
    "print(b)\n",
    "print()\n",
    "\n",
    "a[1:4, 1:4] = b\n",
    "\n",
    "print(\"Second matrix substituted into the middle of the first matrix\")\n",
    "print(a)"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "federal-wayne",
   "metadata": {},
   "source": [
    "## Operations on numpy arrays\n",
    "\n",
    "It is important to remember that arithmetic operations on numpy arrays are always element-wise."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 13,
   "id": "southwest-biotechnology",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[[ 0  1  4]\n",
      " [ 9 16 25]\n",
      " [36 49 64]]\n",
      "\n",
      "[[0.         1.         1.41421356]\n",
      " [1.73205081 2.         2.23606798]\n",
      " [2.44948974 2.64575131 2.82842712]]\n",
      "\n"
     ]
    }
   ],
   "source": [
    "a = np.array([i**2 for i in range(9)]).reshape((3, 3))\n",
    "print(a)\n",
    "print()\n",
    "\n",
    "b = np.array([i**0.5 for i in range(9)]).reshape((3, 3))\n",
    "print(b)\n",
    "print()"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "intensive-gates",
   "metadata": {},
   "source": [
    "### Element-wise sum"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 14,
   "id": "behavioral-safety",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[[ 0.          2.          5.41421356]\n",
      " [10.73205081 18.         27.23606798]\n",
      " [38.44948974 51.64575131 66.82842712]]\n"
     ]
    }
   ],
   "source": [
    "print(a + b)"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "occupied-trial",
   "metadata": {},
   "source": [
    "### Element-wise multiplication"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 15,
   "id": "charming-pleasure",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[[  0.           1.           5.65685425]\n",
      " [ 15.58845727  32.          55.90169944]\n",
      " [ 88.18163074 129.64181424 181.01933598]]\n"
     ]
    }
   ],
   "source": [
    "print(a * b)"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "efficient-league",
   "metadata": {},
   "source": [
    "### Matrix multiplication"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 17,
   "id": "changing-community",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[[ 11.53000978  12.58300524  13.54977648]\n",
      " [ 88.95005649 107.14378278 119.21568782]\n",
      " [241.63783311 303.32808391 341.49835513]]\n",
      "\n",
      "[[ 0.  1.  4.]\n",
      " [ 9. 16. 25.]\n",
      " [36. 49. 64.]]\n"
     ]
    }
   ],
   "source": [
    "print(np.matmul(a, b))\n",
    "print()\n",
    "\n",
    "# Multiplication by the identity matrix (to check it works as expected)\n",
    "id_matrix = np.array([[1.0, 0.0, 0.0], \n",
    "                      [0.0, 1.0, 0.0], \n",
    "                      [0.0, 0.0, 1.0]])\n",
    "\n",
    "print(np.matmul(id_matrix, a))"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "assisted-communications",
   "metadata": {},
   "source": [
    "### Calculating the mean"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 22,
   "id": "defensive-wrong",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[1 4 0 6 4]\n",
      "\n",
      "Mean (by sum):  3.0\n",
      "Mean (by mean): 3.0\n"
     ]
    }
   ],
   "source": [
    "a = np.random.randint(low=0, high=10, size=(5))\n",
    "\n",
    "print(a)\n",
    "print()\n",
    "\n",
    "print(\"Mean (by sum): \", np.sum(a) / len(a))\n",
    "print(\"Mean (by mean):\", np.mean(a))"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "complex-karma",
   "metadata": {},
   "source": [
    "### Calculating the mean of every row"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 30,
   "id": "correct-dietary",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[[4 9 5]\n",
      " [8 9 1]\n",
      " [5 6 4]\n",
      " [3 7 8]\n",
      " [2 1 5]]\n",
      "\n",
      "(5, 3)\n",
      "\n",
      "Mean: [6.         6.         5.         6.         2.66666667]\n",
      "Mean in the original matrix form:\n",
      "[[6.        ]\n",
      " [6.        ]\n",
      " [5.        ]\n",
      " [6.        ]\n",
      " [2.66666667]]\n"
     ]
    }
   ],
   "source": [
    "a = np.random.randint(low=0, high=10, size=(5, 3))\n",
    "\n",
    "print(a)\n",
    "print()\n",
    "print(a.shape)\n",
    "print()\n",
    "\n",
    "print(\"Mean:\", np.sum(a, axis=1) / a.shape[1])\n",
    "\n",
    "print(\"Mean in the original matrix form:\")\n",
    "print((np.sum(a, axis=1) / a.shape[1]).reshape(-1, 1))  # -1 calculates the right size to use all elements"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "indian-orlando",
   "metadata": {},
   "source": [
    "### More complex operations"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 31,
   "id": "presidential-cologne",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Vector to power 2 (element-wise)\n",
      "[1. 4. 9.]\n",
      "\n",
      "Euler number to the power a (element-wise)\n",
      "[ 2.71828183  7.3890561  20.08553692]\n",
      "\n",
      "An even more complex expression\n",
      "[0.61971364 1.89817602 4.84758949]\n"
     ]
    }
   ],
   "source": [
    "a = [1.0, 2.0, 3.0]\n",
    "\n",
    "print(\"Vector to power 2 (element-wise)\")\n",
    "print(np.power(a, 2))\n",
    "print()\n",
    "print(\"Euler number to the power a (element-wise)\")\n",
    "print(np.exp(a))\n",
    "print()\n",
    "print(\"An even more complex expression\")\n",
    "print((np.power(a, 2) + np.exp(a)) / np.sum(a))"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "hearing-street",
   "metadata": {},
   "source": [
    "## Numpy tasks"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "regular-niger",
   "metadata": {},
   "source": [
    "**Task 1.** Calculate the sigmoid (logistic) function on every element of the following numpy array [0.3, 1.2, -1.4, 0.2, -0.1, 0.1, 0.8, -0.25] and print the last 5 elements. Use only vector operations."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "agreed-single",
   "metadata": {},
   "outputs": [],
   "source": [
    "# Write your code here"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "another-catch",
   "metadata": {},
   "source": [
    "**Task 2.** Calculate the dot product of the following two vectors:<br/>\n",
    "$x = [3, 1, 4, 2, 6, 1, 4, 8]$<br/>\n",
    "$y = [5, 2, 3, 12, 2, 4, 17, 11]$<br/>\n",
    "a) by using element-wise mutliplication and np.sum,<br/>\n",
    "b) by using np.dot,<br/>\n",
    "b) by using np.matmul and transposition (x.T)."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "forbidden-journalism",
   "metadata": {},
   "outputs": [],
   "source": [
    "# Write your code here"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "acute-amber",
   "metadata": {},
   "source": [
    "**Task 3.** Calculate the following expression<br/>\n",
    "$$\\frac{1}{1 + e^{-x_0 \\theta_0 - \\ldots - x_9 \\theta_9 - \\theta_{10}}}$$\n",
    "for<br/>\n",
    "$x = [1.2, 2.3, 3.4, -0.7, 4.2, 2.7, -0.5, -2.1, -3.3, 0.2]$<br/>\n",
    "$\\theta = [7.7, 0.33, -2.12, -1.73, 2.9, -5.8, -0.9, 12.11, 3.43, -0.5, 1.65]$<br/>\n",
    "and print the result. Use only vector operations."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "falling-holder",
   "metadata": {},
   "outputs": [],
   "source": [
    "# Write your code here"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "latter-vector",
   "metadata": {},
   "source": [
    "# Pandas"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "contrary-vacuum",
   "metadata": {},
   "source": [
    "## Load datasets\n",
    "\n",
    "- Steam (https://www.kaggle.com/tamber/steam-video-games)\n",
    "\n",
    "- MovieLens (https://grouplens.org/datasets/movielens/)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 32,
   "id": "alert-friday",
   "metadata": {},
   "outputs": [],
   "source": [
    "steam_df = pd.read_csv(os.path.join(\"data\", \"steam\", \"steam-200k.csv\"), \n",
    "                       names=['user-id', 'game-title', 'behavior-name', 'value', 'zero'])\n",
    "\n",
    "ml_ratings_df = pd.read_csv(os.path.join(\"data\", \"movielens_small\", \"ratings.csv\"))\n",
    "ml_movies_df = pd.read_csv(os.path.join(\"data\", \"movielens_small\", \"movies.csv\"))"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "personal-productivity",
   "metadata": {},
   "source": [
    "## Peek into the datasets"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 33,
   "id": "musical-trust",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
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       "    }\n",
       "\n",
       "    .dataframe thead th {\n",
       "        text-align: right;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>user-id</th>\n",
       "      <th>game-title</th>\n",
       "      <th>behavior-name</th>\n",
       "      <th>value</th>\n",
       "      <th>zero</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>0</th>\n",
       "      <td>151603712</td>\n",
       "      <td>The Elder Scrolls V Skyrim</td>\n",
       "      <td>purchase</td>\n",
       "      <td>1.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>151603712</td>\n",
       "      <td>The Elder Scrolls V Skyrim</td>\n",
       "      <td>play</td>\n",
       "      <td>273.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>purchase</td>\n",
       "      <td>1.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>play</td>\n",
       "      <td>87.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>4</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Spore</td>\n",
       "      <td>purchase</td>\n",
       "      <td>1.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>5</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Spore</td>\n",
       "      <td>play</td>\n",
       "      <td>14.9</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>6</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout New Vegas</td>\n",
       "      <td>purchase</td>\n",
       "      <td>1.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>7</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout New Vegas</td>\n",
       "      <td>play</td>\n",
       "      <td>12.1</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>8</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Left 4 Dead 2</td>\n",
       "      <td>purchase</td>\n",
       "      <td>1.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Left 4 Dead 2</td>\n",
       "      <td>play</td>\n",
       "      <td>8.9</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "     user-id                  game-title behavior-name  value  zero\n",
       "0  151603712  The Elder Scrolls V Skyrim      purchase    1.0     0\n",
       "1  151603712  The Elder Scrolls V Skyrim          play  273.0     0\n",
       "2  151603712                   Fallout 4      purchase    1.0     0\n",
       "3  151603712                   Fallout 4          play   87.0     0\n",
       "4  151603712                       Spore      purchase    1.0     0\n",
       "5  151603712                       Spore          play   14.9     0\n",
       "6  151603712           Fallout New Vegas      purchase    1.0     0\n",
       "7  151603712           Fallout New Vegas          play   12.1     0\n",
       "8  151603712               Left 4 Dead 2      purchase    1.0     0\n",
       "9  151603712               Left 4 Dead 2          play    8.9     0"
      ]
     },
     "execution_count": 33,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "steam_df.head(10)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 34,
   "id": "electrical-floor",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
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       "\n",
       "    .dataframe thead th {\n",
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       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>userId</th>\n",
       "      <th>movieId</th>\n",
       "      <th>rating</th>\n",
       "      <th>timestamp</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>0</th>\n",
       "      <td>1</td>\n",
       "      <td>1</td>\n",
       "      <td>4.0</td>\n",
       "      <td>964982703</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>1</td>\n",
       "      <td>3</td>\n",
       "      <td>4.0</td>\n",
       "      <td>964981247</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2</th>\n",
       "      <td>1</td>\n",
       "      <td>6</td>\n",
       "      <td>4.0</td>\n",
       "      <td>964982224</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>1</td>\n",
       "      <td>47</td>\n",
       "      <td>5.0</td>\n",
       "      <td>964983815</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>4</th>\n",
       "      <td>1</td>\n",
       "      <td>50</td>\n",
       "      <td>5.0</td>\n",
       "      <td>964982931</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>5</th>\n",
       "      <td>1</td>\n",
       "      <td>70</td>\n",
       "      <td>3.0</td>\n",
       "      <td>964982400</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>6</th>\n",
       "      <td>1</td>\n",
       "      <td>101</td>\n",
       "      <td>5.0</td>\n",
       "      <td>964980868</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>7</th>\n",
       "      <td>1</td>\n",
       "      <td>110</td>\n",
       "      <td>4.0</td>\n",
       "      <td>964982176</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>8</th>\n",
       "      <td>1</td>\n",
       "      <td>151</td>\n",
       "      <td>5.0</td>\n",
       "      <td>964984041</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9</th>\n",
       "      <td>1</td>\n",
       "      <td>157</td>\n",
       "      <td>5.0</td>\n",
       "      <td>964984100</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "   userId  movieId  rating  timestamp\n",
       "0       1        1     4.0  964982703\n",
       "1       1        3     4.0  964981247\n",
       "2       1        6     4.0  964982224\n",
       "3       1       47     5.0  964983815\n",
       "4       1       50     5.0  964982931\n",
       "5       1       70     3.0  964982400\n",
       "6       1      101     5.0  964980868\n",
       "7       1      110     4.0  964982176\n",
       "8       1      151     5.0  964984041\n",
       "9       1      157     5.0  964984100"
      ]
     },
     "execution_count": 34,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "ml_ratings_df.head(10)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 36,
   "id": "cordless-daniel",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
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       "\n",
       "    .dataframe tbody tr th {\n",
       "        vertical-align: top;\n",
       "    }\n",
       "\n",
       "    .dataframe thead th {\n",
       "        text-align: right;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>movieId</th>\n",
       "      <th>title</th>\n",
       "      <th>genres</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>0</th>\n",
       "      <td>1</td>\n",
       "      <td>Toy Story (1995)</td>\n",
       "      <td>Adventure|Animation|Children|Comedy|Fantasy</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>2</td>\n",
       "      <td>Jumanji (1995)</td>\n",
       "      <td>Adventure|Children|Fantasy</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2</th>\n",
       "      <td>3</td>\n",
       "      <td>Grumpier Old Men (1995)</td>\n",
       "      <td>Comedy|Romance</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>4</td>\n",
       "      <td>Waiting to Exhale (1995)</td>\n",
       "      <td>Comedy|Drama|Romance</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>4</th>\n",
       "      <td>5</td>\n",
       "      <td>Father of the Bride Part II (1995)</td>\n",
       "      <td>Comedy</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>5</th>\n",
       "      <td>6</td>\n",
       "      <td>Heat (1995)</td>\n",
       "      <td>Action|Crime|Thriller</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>6</th>\n",
       "      <td>7</td>\n",
       "      <td>Sabrina (1995)</td>\n",
       "      <td>Comedy|Romance</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>7</th>\n",
       "      <td>8</td>\n",
       "      <td>Tom and Huck (1995)</td>\n",
       "      <td>Adventure|Children</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>8</th>\n",
       "      <td>9</td>\n",
       "      <td>Sudden Death (1995)</td>\n",
       "      <td>Action</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9</th>\n",
       "      <td>10</td>\n",
       "      <td>GoldenEye (1995)</td>\n",
       "      <td>Action|Adventure|Thriller</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "   movieId                               title  \\\n",
       "0        1                    Toy Story (1995)   \n",
       "1        2                      Jumanji (1995)   \n",
       "2        3             Grumpier Old Men (1995)   \n",
       "3        4            Waiting to Exhale (1995)   \n",
       "4        5  Father of the Bride Part II (1995)   \n",
       "5        6                         Heat (1995)   \n",
       "6        7                      Sabrina (1995)   \n",
       "7        8                 Tom and Huck (1995)   \n",
       "8        9                 Sudden Death (1995)   \n",
       "9       10                    GoldenEye (1995)   \n",
       "\n",
       "                                        genres  \n",
       "0  Adventure|Animation|Children|Comedy|Fantasy  \n",
       "1                   Adventure|Children|Fantasy  \n",
       "2                               Comedy|Romance  \n",
       "3                         Comedy|Drama|Romance  \n",
       "4                                       Comedy  \n",
       "5                        Action|Crime|Thriller  \n",
       "6                               Comedy|Romance  \n",
       "7                           Adventure|Children  \n",
       "8                                       Action  \n",
       "9                    Action|Adventure|Thriller  "
      ]
     },
     "execution_count": 36,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "ml_movies_df.head(10)"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "alpha-portal",
   "metadata": {},
   "source": [
    "## Merge both MovieLens DataFrames into one"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 39,
   "id": "affecting-disclosure",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
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       "    }\n",
       "\n",
       "    .dataframe thead th {\n",
       "        text-align: right;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>userId</th>\n",
       "      <th>movieId</th>\n",
       "      <th>rating</th>\n",
       "      <th>timestamp</th>\n",
       "      <th>title</th>\n",
       "      <th>genres</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>0</th>\n",
       "      <td>1</td>\n",
       "      <td>1</td>\n",
       "      <td>4.0</td>\n",
       "      <td>964982703</td>\n",
       "      <td>Toy Story (1995)</td>\n",
       "      <td>Adventure|Animation|Children|Comedy|Fantasy</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>5</td>\n",
       "      <td>1</td>\n",
       "      <td>4.0</td>\n",
       "      <td>847434962</td>\n",
       "      <td>Toy Story (1995)</td>\n",
       "      <td>Adventure|Animation|Children|Comedy|Fantasy</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2</th>\n",
       "      <td>7</td>\n",
       "      <td>1</td>\n",
       "      <td>4.5</td>\n",
       "      <td>1106635946</td>\n",
       "      <td>Toy Story (1995)</td>\n",
       "      <td>Adventure|Animation|Children|Comedy|Fantasy</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>15</td>\n",
       "      <td>1</td>\n",
       "      <td>2.5</td>\n",
       "      <td>1510577970</td>\n",
       "      <td>Toy Story (1995)</td>\n",
       "      <td>Adventure|Animation|Children|Comedy|Fantasy</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>4</th>\n",
       "      <td>17</td>\n",
       "      <td>1</td>\n",
       "      <td>4.5</td>\n",
       "      <td>1305696483</td>\n",
       "      <td>Toy Story (1995)</td>\n",
       "      <td>Adventure|Animation|Children|Comedy|Fantasy</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>5</th>\n",
       "      <td>18</td>\n",
       "      <td>1</td>\n",
       "      <td>3.5</td>\n",
       "      <td>1455209816</td>\n",
       "      <td>Toy Story (1995)</td>\n",
       "      <td>Adventure|Animation|Children|Comedy|Fantasy</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>6</th>\n",
       "      <td>19</td>\n",
       "      <td>1</td>\n",
       "      <td>4.0</td>\n",
       "      <td>965705637</td>\n",
       "      <td>Toy Story (1995)</td>\n",
       "      <td>Adventure|Animation|Children|Comedy|Fantasy</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>7</th>\n",
       "      <td>21</td>\n",
       "      <td>1</td>\n",
       "      <td>3.5</td>\n",
       "      <td>1407618878</td>\n",
       "      <td>Toy Story (1995)</td>\n",
       "      <td>Adventure|Animation|Children|Comedy|Fantasy</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>8</th>\n",
       "      <td>27</td>\n",
       "      <td>1</td>\n",
       "      <td>3.0</td>\n",
       "      <td>962685262</td>\n",
       "      <td>Toy Story (1995)</td>\n",
       "      <td>Adventure|Animation|Children|Comedy|Fantasy</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9</th>\n",
       "      <td>31</td>\n",
       "      <td>1</td>\n",
       "      <td>5.0</td>\n",
       "      <td>850466616</td>\n",
       "      <td>Toy Story (1995)</td>\n",
       "      <td>Adventure|Animation|Children|Comedy|Fantasy</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "   userId  movieId  rating   timestamp             title  \\\n",
       "0       1        1     4.0   964982703  Toy Story (1995)   \n",
       "1       5        1     4.0   847434962  Toy Story (1995)   \n",
       "2       7        1     4.5  1106635946  Toy Story (1995)   \n",
       "3      15        1     2.5  1510577970  Toy Story (1995)   \n",
       "4      17        1     4.5  1305696483  Toy Story (1995)   \n",
       "5      18        1     3.5  1455209816  Toy Story (1995)   \n",
       "6      19        1     4.0   965705637  Toy Story (1995)   \n",
       "7      21        1     3.5  1407618878  Toy Story (1995)   \n",
       "8      27        1     3.0   962685262  Toy Story (1995)   \n",
       "9      31        1     5.0   850466616  Toy Story (1995)   \n",
       "\n",
       "                                        genres  \n",
       "0  Adventure|Animation|Children|Comedy|Fantasy  \n",
       "1  Adventure|Animation|Children|Comedy|Fantasy  \n",
       "2  Adventure|Animation|Children|Comedy|Fantasy  \n",
       "3  Adventure|Animation|Children|Comedy|Fantasy  \n",
       "4  Adventure|Animation|Children|Comedy|Fantasy  \n",
       "5  Adventure|Animation|Children|Comedy|Fantasy  \n",
       "6  Adventure|Animation|Children|Comedy|Fantasy  \n",
       "7  Adventure|Animation|Children|Comedy|Fantasy  \n",
       "8  Adventure|Animation|Children|Comedy|Fantasy  \n",
       "9  Adventure|Animation|Children|Comedy|Fantasy  "
      ]
     },
     "execution_count": 39,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "ml_df = pd.merge(ml_ratings_df, ml_movies_df, on='movieId')\n",
    "ml_df.head(10)"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "lightweight-constitution",
   "metadata": {},
   "source": [
    "## Choosing a row, a column or several columns"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 40,
   "id": "excited-interface",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>user-id</th>\n",
       "      <th>game-title</th>\n",
       "      <th>behavior-name</th>\n",
       "      <th>value</th>\n",
       "      <th>zero</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>0</th>\n",
       "      <td>151603712</td>\n",
       "      <td>The Elder Scrolls V Skyrim</td>\n",
       "      <td>purchase</td>\n",
       "      <td>1.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>151603712</td>\n",
       "      <td>The Elder Scrolls V Skyrim</td>\n",
       "      <td>play</td>\n",
       "      <td>273.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>purchase</td>\n",
       "      <td>1.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>play</td>\n",
       "      <td>87.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>4</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Spore</td>\n",
       "      <td>purchase</td>\n",
       "      <td>1.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>5</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Spore</td>\n",
       "      <td>play</td>\n",
       "      <td>14.9</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>6</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout New Vegas</td>\n",
       "      <td>purchase</td>\n",
       "      <td>1.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>7</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout New Vegas</td>\n",
       "      <td>play</td>\n",
       "      <td>12.1</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>8</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Left 4 Dead 2</td>\n",
       "      <td>purchase</td>\n",
       "      <td>1.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Left 4 Dead 2</td>\n",
       "      <td>play</td>\n",
       "      <td>8.9</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>"
      ],
      "text/plain": [
       "<IPython.core.display.HTML object>"
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    },
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Choosing rows by index\n"
     ]
    },
    {
     "data": {
      "text/html": [
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>user-id</th>\n",
       "      <th>game-title</th>\n",
       "      <th>behavior-name</th>\n",
       "      <th>value</th>\n",
       "      <th>zero</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>play</td>\n",
       "      <td>87.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>4</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Spore</td>\n",
       "      <td>purchase</td>\n",
       "      <td>1.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>5</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Spore</td>\n",
       "      <td>play</td>\n",
       "      <td>14.9</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>"
      ],
      "text/plain": [
       "<IPython.core.display.HTML object>"
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    },
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Choosing rows by position\n"
     ]
    },
    {
     "data": {
      "text/html": [
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>user-id</th>\n",
       "      <th>game-title</th>\n",
       "      <th>behavior-name</th>\n",
       "      <th>value</th>\n",
       "      <th>zero</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>play</td>\n",
       "      <td>87.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>4</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Spore</td>\n",
       "      <td>purchase</td>\n",
       "      <td>1.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>5</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Spore</td>\n",
       "      <td>play</td>\n",
       "      <td>14.9</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>"
      ],
      "text/plain": [
       "<IPython.core.display.HTML object>"
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    }
   ],
   "source": [
    "display(HTML(steam_df.head(10).to_html()))\n",
    "\n",
    "# Choosing rows by index\n",
    "chosen_df = steam_df[3:6]\n",
    "\n",
    "print(\"Choosing rows by index\")\n",
    "display(HTML(chosen_df.head(10).to_html()))\n",
    "\n",
    "# Choosing rows by position\n",
    "chosen_df = steam_df.iloc[3:6]\n",
    "\n",
    "print(\"Choosing rows by position\")\n",
    "display(HTML(chosen_df.head(10).to_html()))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 42,
   "id": "reflected-banner",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "0    The Elder Scrolls V Skyrim\n",
      "1    The Elder Scrolls V Skyrim\n",
      "2                     Fallout 4\n",
      "3                     Fallout 4\n",
      "4                         Spore\n",
      "5                         Spore\n",
      "6             Fallout New Vegas\n",
      "7             Fallout New Vegas\n",
      "8                 Left 4 Dead 2\n",
      "9                 Left 4 Dead 2\n",
      "Name: game-title, dtype: object\n"
     ]
    }
   ],
   "source": [
    "# Choosing a column\n",
    "chosen_df = steam_df['game-title']\n",
    "\n",
    "print(chosen_df.head(10))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 43,
   "id": "efficient-humidity",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>user-id</th>\n",
       "      <th>game-title</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>0</th>\n",
       "      <td>151603712</td>\n",
       "      <td>The Elder Scrolls V Skyrim</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>151603712</td>\n",
       "      <td>The Elder Scrolls V Skyrim</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout 4</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout 4</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>4</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Spore</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>5</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Spore</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>6</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout New Vegas</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>7</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout New Vegas</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>8</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Left 4 Dead 2</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Left 4 Dead 2</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>"
      ],
      "text/plain": [
       "<IPython.core.display.HTML object>"
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    }
   ],
   "source": [
    "# Choosing several columns\n",
    "chosen_df = steam_df[['user-id', 'game-title']]\n",
    "\n",
    "display(HTML(chosen_df.head(10).to_html()))"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "popular-cause",
   "metadata": {},
   "source": [
    "### Splitting the dataset into training and test set"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 45,
   "id": "continuous-cheat",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Shuffled range of indices\n",
      "[ 88886  27084  35588  56116 183664  34019 190384 138109  48325  94171\n",
      " 163304  35071  45875 187591 107927  62332  97588   3784    669  75931]\n",
      "\n"
     ]
    },
    {
     "data": {
      "text/html": [
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>user-id</th>\n",
       "      <th>game-title</th>\n",
       "      <th>behavior-name</th>\n",
       "      <th>value</th>\n",
       "      <th>zero</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>88886</th>\n",
       "      <td>173434036</td>\n",
       "      <td>Mortal Kombat X</td>\n",
       "      <td>purchase</td>\n",
       "      <td>1.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>27084</th>\n",
       "      <td>80779496</td>\n",
       "      <td>Sins of a Solar Empire Trinity</td>\n",
       "      <td>play</td>\n",
       "      <td>0.6</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>35588</th>\n",
       "      <td>109669093</td>\n",
       "      <td>Killing Floor</td>\n",
       "      <td>play</td>\n",
       "      <td>225.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>56116</th>\n",
       "      <td>94269421</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>play</td>\n",
       "      <td>10.1</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>183664</th>\n",
       "      <td>279406744</td>\n",
       "      <td>BLOCKADE 3D</td>\n",
       "      <td>purchase</td>\n",
       "      <td>1.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>34019</th>\n",
       "      <td>126269125</td>\n",
       "      <td>Grand Theft Auto San Andreas</td>\n",
       "      <td>purchase</td>\n",
       "      <td>1.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>190384</th>\n",
       "      <td>71335402</td>\n",
       "      <td>7 Days to Die</td>\n",
       "      <td>play</td>\n",
       "      <td>8.2</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>138109</th>\n",
       "      <td>156818121</td>\n",
       "      <td>Half-Life 2</td>\n",
       "      <td>play</td>\n",
       "      <td>22.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>48325</th>\n",
       "      <td>114617787</td>\n",
       "      <td>Garry's Mod</td>\n",
       "      <td>play</td>\n",
       "      <td>1.2</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>94171</th>\n",
       "      <td>156615447</td>\n",
       "      <td>LEGO MARVEL Super Heroes</td>\n",
       "      <td>play</td>\n",
       "      <td>1.7</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>"
      ],
      "text/plain": [
       "<IPython.core.display.HTML object>"
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    },
    {
     "data": {
      "text/html": [
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>user-id</th>\n",
       "      <th>game-title</th>\n",
       "      <th>behavior-name</th>\n",
       "      <th>value</th>\n",
       "      <th>zero</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>170080</th>\n",
       "      <td>81591317</td>\n",
       "      <td>Warframe</td>\n",
       "      <td>purchase</td>\n",
       "      <td>1.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>85279</th>\n",
       "      <td>44472980</td>\n",
       "      <td>Serious Sam Double D XXL</td>\n",
       "      <td>purchase</td>\n",
       "      <td>1.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>132916</th>\n",
       "      <td>45592640</td>\n",
       "      <td>Penumbra Black Plague</td>\n",
       "      <td>purchase</td>\n",
       "      <td>1.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>12193</th>\n",
       "      <td>64787956</td>\n",
       "      <td>Always Sometimes Monsters</td>\n",
       "      <td>purchase</td>\n",
       "      <td>1.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>46374</th>\n",
       "      <td>192538478</td>\n",
       "      <td>Heroes &amp; Generals</td>\n",
       "      <td>play</td>\n",
       "      <td>0.4</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>89823</th>\n",
       "      <td>1936551</td>\n",
       "      <td>Castle Crashers</td>\n",
       "      <td>purchase</td>\n",
       "      <td>1.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>179113</th>\n",
       "      <td>132196353</td>\n",
       "      <td>Knights and Merchants</td>\n",
       "      <td>purchase</td>\n",
       "      <td>1.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>144002</th>\n",
       "      <td>13190476</td>\n",
       "      <td>Blood Bowl 2</td>\n",
       "      <td>play</td>\n",
       "      <td>6.3</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>35416</th>\n",
       "      <td>60296891</td>\n",
       "      <td>Mirror's Edge</td>\n",
       "      <td>purchase</td>\n",
       "      <td>1.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>120786</th>\n",
       "      <td>62990992</td>\n",
       "      <td>Rome Total War</td>\n",
       "      <td>purchase</td>\n",
       "      <td>1.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>"
      ],
      "text/plain": [
       "<IPython.core.display.HTML object>"
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    },
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "160000\n",
      "40000\n"
     ]
    }
   ],
   "source": [
    "shuffle = np.array(list(range(len(steam_df))))\n",
    "\n",
    "# alternatively\n",
    "\n",
    "shuffle = np.arange(len(steam_df))\n",
    "\n",
    "np.random.shuffle(shuffle)\n",
    "# shuffle = list(shuffle)\n",
    "print(\"Shuffled range of indices\")\n",
    "print(shuffle[:20])\n",
    "print()\n",
    "\n",
    "train_test_split = 0.8\n",
    "split_index = int(len(steam_df) * train_test_split)\n",
    "\n",
    "training_set = steam_df.iloc[shuffle[:split_index]]\n",
    "test_set = steam_df.iloc[shuffle[split_index:]]\n",
    "\n",
    "display(HTML(training_set.head(10).to_html()))\n",
    "\n",
    "display(HTML(test_set.head(10).to_html()))\n",
    "\n",
    "print(len(training_set))\n",
    "print(len(test_set))"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "outside-twist",
   "metadata": {},
   "source": [
    "## Filtering"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "otherwise-rachel",
   "metadata": {},
   "source": [
    "### Filtering columns"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 46,
   "id": "numerical-pride",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>user-id</th>\n",
       "      <th>game-title</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>0</th>\n",
       "      <td>151603712</td>\n",
       "      <td>The Elder Scrolls V Skyrim</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>151603712</td>\n",
       "      <td>The Elder Scrolls V Skyrim</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout 4</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout 4</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>4</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Spore</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>5</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Spore</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>6</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout New Vegas</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>7</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout New Vegas</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>8</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Left 4 Dead 2</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Left 4 Dead 2</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>"
      ],
      "text/plain": [
       "<IPython.core.display.HTML object>"
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    }
   ],
   "source": [
    "chosen_df = steam_df.loc[:, ['user-id', 'game-title']]\n",
    "\n",
    "display(HTML(chosen_df.head(10).to_html()))"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "interior-cleaner",
   "metadata": {},
   "source": [
    "### Filtering rows"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 47,
   "id": "marine-growth",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "0    False\n",
      "1    False\n",
      "2     True\n",
      "3     True\n",
      "4    False\n",
      "5    False\n",
      "6    False\n",
      "7    False\n",
      "8    False\n",
      "9    False\n",
      "Name: game-title, dtype: bool\n"
     ]
    },
    {
     "data": {
      "text/html": [
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>user-id</th>\n",
       "      <th>game-title</th>\n",
       "      <th>behavior-name</th>\n",
       "      <th>value</th>\n",
       "      <th>zero</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>2</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>purchase</td>\n",
       "      <td>1.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>play</td>\n",
       "      <td>87.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3187</th>\n",
       "      <td>87445402</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>purchase</td>\n",
       "      <td>1.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3188</th>\n",
       "      <td>87445402</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>play</td>\n",
       "      <td>83.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>5683</th>\n",
       "      <td>25096601</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>purchase</td>\n",
       "      <td>1.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>5684</th>\n",
       "      <td>25096601</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>play</td>\n",
       "      <td>1.6</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>6219</th>\n",
       "      <td>211925330</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>purchase</td>\n",
       "      <td>1.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>6220</th>\n",
       "      <td>211925330</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>play</td>\n",
       "      <td>133.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>7300</th>\n",
       "      <td>115396529</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>purchase</td>\n",
       "      <td>1.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>7301</th>\n",
       "      <td>115396529</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>play</td>\n",
       "      <td>17.9</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>"
      ],
      "text/plain": [
       "<IPython.core.display.HTML object>"
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    }
   ],
   "source": [
    "condition = steam_df['game-title'] == 'Fallout 4'\n",
    "\n",
    "print(condition.head(10))\n",
    "\n",
    "chosen_df = steam_df.loc[condition]\n",
    "\n",
    "display(HTML(chosen_df.head(10).to_html()))"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "functioning-condition",
   "metadata": {},
   "source": [
    "### Filtering rows and columns at once"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 48,
   "id": "advanced-religion",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>user-id</th>\n",
       "      <th>game-title</th>\n",
       "      <th>value</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>87.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3188</th>\n",
       "      <td>87445402</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>83.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>5684</th>\n",
       "      <td>25096601</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>1.6</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>6220</th>\n",
       "      <td>211925330</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>133.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>7301</th>\n",
       "      <td>115396529</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>17.9</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>7527</th>\n",
       "      <td>4834220</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>19.8</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>7617</th>\n",
       "      <td>65229865</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>0.5</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>7712</th>\n",
       "      <td>65958466</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>123.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9963</th>\n",
       "      <td>91800733</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>63.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>10700</th>\n",
       "      <td>43913966</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>65.0</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>"
      ],
      "text/plain": [
       "<IPython.core.display.HTML object>"
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    }
   ],
   "source": [
    "condition = (steam_df['game-title'] == 'Fallout 4') & (steam_df['behavior-name'] == 'play')\n",
    "\n",
    "chosen_df = steam_df.loc[condition, ['user-id', 'game-title', 'value']]\n",
    "\n",
    "display(HTML(chosen_df.head(10).to_html()))"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "frequent-match",
   "metadata": {},
   "source": [
    "## Simple operations on columns"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "described-sister",
   "metadata": {},
   "source": [
    "### Multiply a column by 2"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 51,
   "id": "injured-sweet",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>user-id</th>\n",
       "      <th>game-title</th>\n",
       "      <th>behavior-name</th>\n",
       "      <th>value</th>\n",
       "      <th>zero</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>0</th>\n",
       "      <td>151603712</td>\n",
       "      <td>The Elder Scrolls V Skyrim</td>\n",
       "      <td>purchase</td>\n",
       "      <td>1.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>151603712</td>\n",
       "      <td>The Elder Scrolls V Skyrim</td>\n",
       "      <td>play</td>\n",
       "      <td>273.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>purchase</td>\n",
       "      <td>1.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>play</td>\n",
       "      <td>87.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>4</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Spore</td>\n",
       "      <td>purchase</td>\n",
       "      <td>1.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>5</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Spore</td>\n",
       "      <td>play</td>\n",
       "      <td>14.9</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>6</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout New Vegas</td>\n",
       "      <td>purchase</td>\n",
       "      <td>1.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>7</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout New Vegas</td>\n",
       "      <td>play</td>\n",
       "      <td>12.1</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>8</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Left 4 Dead 2</td>\n",
       "      <td>purchase</td>\n",
       "      <td>1.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Left 4 Dead 2</td>\n",
       "      <td>play</td>\n",
       "      <td>8.9</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>"
      ],
      "text/plain": [
       "<IPython.core.display.HTML object>"
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    },
    {
     "data": {
      "text/html": [
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>user-id</th>\n",
       "      <th>game-title</th>\n",
       "      <th>behavior-name</th>\n",
       "      <th>value</th>\n",
       "      <th>zero</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>0</th>\n",
       "      <td>151603712</td>\n",
       "      <td>The Elder Scrolls V Skyrim</td>\n",
       "      <td>purchase</td>\n",
       "      <td>2.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>151603712</td>\n",
       "      <td>The Elder Scrolls V Skyrim</td>\n",
       "      <td>play</td>\n",
       "      <td>546.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>purchase</td>\n",
       "      <td>2.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>play</td>\n",
       "      <td>174.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>4</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Spore</td>\n",
       "      <td>purchase</td>\n",
       "      <td>2.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>5</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Spore</td>\n",
       "      <td>play</td>\n",
       "      <td>29.8</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>6</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout New Vegas</td>\n",
       "      <td>purchase</td>\n",
       "      <td>2.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>7</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout New Vegas</td>\n",
       "      <td>play</td>\n",
       "      <td>24.2</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>8</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Left 4 Dead 2</td>\n",
       "      <td>purchase</td>\n",
       "      <td>2.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Left 4 Dead 2</td>\n",
       "      <td>play</td>\n",
       "      <td>17.8</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>"
      ],
      "text/plain": [
       "<IPython.core.display.HTML object>"
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    }
   ],
   "source": [
    "steam_df_copy = steam_df.copy()\n",
    "\n",
    "display(HTML(steam_df_copy.head(10).to_html()))\n",
    "\n",
    "steam_df_copy.loc[:, 'value'] = steam_df_copy['value'] * 2\n",
    "\n",
    "display(HTML(steam_df_copy.head(10).to_html()))"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "executed-processor",
   "metadata": {},
   "source": [
    "### Choose the first n letters of a string"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 52,
   "id": "forbidden-mining",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>movieId</th>\n",
       "      <th>title</th>\n",
       "      <th>genres</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>0</th>\n",
       "      <td>1</td>\n",
       "      <td>Toy Story (1995)</td>\n",
       "      <td>Adventure|Animation|Children|Comedy|Fantasy</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>2</td>\n",
       "      <td>Jumanji (1995)</td>\n",
       "      <td>Adventure|Children|Fantasy</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2</th>\n",
       "      <td>3</td>\n",
       "      <td>Grumpier Old Men (1995)</td>\n",
       "      <td>Comedy|Romance</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>4</td>\n",
       "      <td>Waiting to Exhale (1995)</td>\n",
       "      <td>Comedy|Drama|Romance</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>4</th>\n",
       "      <td>5</td>\n",
       "      <td>Father of the Bride Part II (1995)</td>\n",
       "      <td>Comedy</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>5</th>\n",
       "      <td>6</td>\n",
       "      <td>Heat (1995)</td>\n",
       "      <td>Action|Crime|Thriller</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>6</th>\n",
       "      <td>7</td>\n",
       "      <td>Sabrina (1995)</td>\n",
       "      <td>Comedy|Romance</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>7</th>\n",
       "      <td>8</td>\n",
       "      <td>Tom and Huck (1995)</td>\n",
       "      <td>Adventure|Children</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>8</th>\n",
       "      <td>9</td>\n",
       "      <td>Sudden Death (1995)</td>\n",
       "      <td>Action</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9</th>\n",
       "      <td>10</td>\n",
       "      <td>GoldenEye (1995)</td>\n",
       "      <td>Action|Adventure|Thriller</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>"
      ],
      "text/plain": [
       "<IPython.core.display.HTML object>"
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    },
    {
     "data": {
      "text/html": [
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>movieId</th>\n",
       "      <th>title</th>\n",
       "      <th>genres</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>0</th>\n",
       "      <td>1</td>\n",
       "      <td>Toy St</td>\n",
       "      <td>Adventure|Animation|Children|Comedy|Fantasy</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>2</td>\n",
       "      <td>Jumanj</td>\n",
       "      <td>Adventure|Children|Fantasy</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2</th>\n",
       "      <td>3</td>\n",
       "      <td>Grumpi</td>\n",
       "      <td>Comedy|Romance</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>4</td>\n",
       "      <td>Waitin</td>\n",
       "      <td>Comedy|Drama|Romance</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>4</th>\n",
       "      <td>5</td>\n",
       "      <td>Father</td>\n",
       "      <td>Comedy</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>5</th>\n",
       "      <td>6</td>\n",
       "      <td>Heat (</td>\n",
       "      <td>Action|Crime|Thriller</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>6</th>\n",
       "      <td>7</td>\n",
       "      <td>Sabrin</td>\n",
       "      <td>Comedy|Romance</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>7</th>\n",
       "      <td>8</td>\n",
       "      <td>Tom an</td>\n",
       "      <td>Adventure|Children</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>8</th>\n",
       "      <td>9</td>\n",
       "      <td>Sudden</td>\n",
       "      <td>Action</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9</th>\n",
       "      <td>10</td>\n",
       "      <td>Golden</td>\n",
       "      <td>Action|Adventure|Thriller</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>"
      ],
      "text/plain": [
       "<IPython.core.display.HTML object>"
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    }
   ],
   "source": [
    "ml_movies_df_copy = ml_movies_df.copy()\n",
    "\n",
    "display(HTML(ml_movies_df_copy.head(10).to_html()))\n",
    "\n",
    "ml_movies_df_copy.loc[:, 'title'] = ml_movies_df_copy['title'].str[:6]\n",
    "\n",
    "display(HTML(ml_movies_df_copy.head(10).to_html()))"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "incorporated-entrance",
   "metadata": {},
   "source": [
    "### Take the mean of a column"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 53,
   "id": "selected-trial",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "17.874384000000475\n",
      "17.874384000000475\n"
     ]
    }
   ],
   "source": [
    "# Option 1\n",
    "print(steam_df['value'].mean())\n",
    "\n",
    "# Option 2\n",
    "print(np.mean(steam_df['value']))"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "discrete-cheese",
   "metadata": {},
   "source": [
    "### Simple operation on filtered data"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 54,
   "id": "bridal-greenhouse",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>user-id</th>\n",
       "      <th>game-title</th>\n",
       "      <th>behavior-name</th>\n",
       "      <th>value</th>\n",
       "      <th>zero</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>151603712</td>\n",
       "      <td>The Elder Scrolls V Skyrim</td>\n",
       "      <td>play</td>\n",
       "      <td>273.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>play</td>\n",
       "      <td>87.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>73</th>\n",
       "      <td>59945701</td>\n",
       "      <td>The Elder Scrolls V Skyrim</td>\n",
       "      <td>play</td>\n",
       "      <td>58.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1066</th>\n",
       "      <td>92107940</td>\n",
       "      <td>The Elder Scrolls V Skyrim</td>\n",
       "      <td>play</td>\n",
       "      <td>110.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1168</th>\n",
       "      <td>250006052</td>\n",
       "      <td>The Elder Scrolls V Skyrim</td>\n",
       "      <td>play</td>\n",
       "      <td>465.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1388</th>\n",
       "      <td>11373749</td>\n",
       "      <td>The Elder Scrolls V Skyrim</td>\n",
       "      <td>play</td>\n",
       "      <td>220.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2065</th>\n",
       "      <td>54103616</td>\n",
       "      <td>The Elder Scrolls V Skyrim</td>\n",
       "      <td>play</td>\n",
       "      <td>35.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2569</th>\n",
       "      <td>56038151</td>\n",
       "      <td>The Elder Scrolls V Skyrim</td>\n",
       "      <td>play</td>\n",
       "      <td>14.6</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3188</th>\n",
       "      <td>87445402</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>play</td>\n",
       "      <td>83.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3233</th>\n",
       "      <td>94088853</td>\n",
       "      <td>The Elder Scrolls V Skyrim</td>\n",
       "      <td>play</td>\n",
       "      <td>320.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>"
      ],
      "text/plain": [
       "<IPython.core.display.HTML object>"
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    },
    {
     "data": {
      "text/html": [
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>user-id</th>\n",
       "      <th>game-title</th>\n",
       "      <th>behavior-name</th>\n",
       "      <th>value</th>\n",
       "      <th>zero</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>151603712</td>\n",
       "      <td>The Elder Scrolls V Skyrim</td>\n",
       "      <td>play</td>\n",
       "      <td>273.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>play</td>\n",
       "      <td>174.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>73</th>\n",
       "      <td>59945701</td>\n",
       "      <td>The Elder Scrolls V Skyrim</td>\n",
       "      <td>play</td>\n",
       "      <td>58.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1066</th>\n",
       "      <td>92107940</td>\n",
       "      <td>The Elder Scrolls V Skyrim</td>\n",
       "      <td>play</td>\n",
       "      <td>110.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1168</th>\n",
       "      <td>250006052</td>\n",
       "      <td>The Elder Scrolls V Skyrim</td>\n",
       "      <td>play</td>\n",
       "      <td>465.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1388</th>\n",
       "      <td>11373749</td>\n",
       "      <td>The Elder Scrolls V Skyrim</td>\n",
       "      <td>play</td>\n",
       "      <td>220.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2065</th>\n",
       "      <td>54103616</td>\n",
       "      <td>The Elder Scrolls V Skyrim</td>\n",
       "      <td>play</td>\n",
       "      <td>35.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2569</th>\n",
       "      <td>56038151</td>\n",
       "      <td>The Elder Scrolls V Skyrim</td>\n",
       "      <td>play</td>\n",
       "      <td>14.6</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3188</th>\n",
       "      <td>87445402</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>play</td>\n",
       "      <td>166.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3233</th>\n",
       "      <td>94088853</td>\n",
       "      <td>The Elder Scrolls V Skyrim</td>\n",
       "      <td>play</td>\n",
       "      <td>320.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>"
      ],
      "text/plain": [
       "<IPython.core.display.HTML object>"
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    }
   ],
   "source": [
    "steam_df_copy = steam_df.loc[((steam_df['game-title'] == 'Fallout 4') | (steam_df['game-title'] == 'The Elder Scrolls V Skyrim')) \n",
    "                             & (steam_df['behavior-name'] == 'play')].copy()\n",
    "\n",
    "display(HTML(steam_df_copy.head(10).to_html()))\n",
    "\n",
    "condition = (steam_df_copy['game-title'] == 'Fallout 4') & (steam_df_copy['behavior-name'] == 'play')\n",
    "\n",
    "steam_df_copy.loc[condition, 'value'] = steam_df_copy.loc[condition, 'value'] * 2\n",
    "\n",
    "display(HTML(steam_df_copy.head(10).to_html()))"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "relevant-strap",
   "metadata": {},
   "source": [
    "## Advanced operations on columns"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 55,
   "id": "female-french",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>user-id</th>\n",
       "      <th>game-title</th>\n",
       "      <th>behavior-name</th>\n",
       "      <th>value</th>\n",
       "      <th>zero</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>151603712</td>\n",
       "      <td>The Elder Scrolls V Skyrim</td>\n",
       "      <td>play</td>\n",
       "      <td>273.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>play</td>\n",
       "      <td>87.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>5</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Spore</td>\n",
       "      <td>play</td>\n",
       "      <td>14.9</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>7</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout New Vegas</td>\n",
       "      <td>play</td>\n",
       "      <td>12.1</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Left 4 Dead 2</td>\n",
       "      <td>play</td>\n",
       "      <td>8.9</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>11</th>\n",
       "      <td>151603712</td>\n",
       "      <td>HuniePop</td>\n",
       "      <td>play</td>\n",
       "      <td>8.5</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>13</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Path of Exile</td>\n",
       "      <td>play</td>\n",
       "      <td>8.1</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>15</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Poly Bridge</td>\n",
       "      <td>play</td>\n",
       "      <td>7.5</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>17</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Left 4 Dead</td>\n",
       "      <td>play</td>\n",
       "      <td>3.3</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>19</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Team Fortress 2</td>\n",
       "      <td>play</td>\n",
       "      <td>2.8</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>"
      ],
      "text/plain": [
       "<IPython.core.display.HTML object>"
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    },
    {
     "data": {
      "text/html": [
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>user-id</th>\n",
       "      <th>game-title</th>\n",
       "      <th>behavior-name</th>\n",
       "      <th>value</th>\n",
       "      <th>zero</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>151603712</td>\n",
       "      <td>The Elder Scrolls V Skyrim</td>\n",
       "      <td>play</td>\n",
       "      <td>4.000000</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>play</td>\n",
       "      <td>4.000000</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>5</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Spore</td>\n",
       "      <td>play</td>\n",
       "      <td>2.766319</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>7</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout New Vegas</td>\n",
       "      <td>play</td>\n",
       "      <td>2.572612</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Left 4 Dead 2</td>\n",
       "      <td>play</td>\n",
       "      <td>2.292535</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>11</th>\n",
       "      <td>151603712</td>\n",
       "      <td>HuniePop</td>\n",
       "      <td>play</td>\n",
       "      <td>2.251292</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>13</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Path of Exile</td>\n",
       "      <td>play</td>\n",
       "      <td>2.208274</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>15</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Poly Bridge</td>\n",
       "      <td>play</td>\n",
       "      <td>2.140066</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>17</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Left 4 Dead</td>\n",
       "      <td>play</td>\n",
       "      <td>1.458615</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>19</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Team Fortress 2</td>\n",
       "      <td>play</td>\n",
       "      <td>1.335001</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>"
      ],
      "text/plain": [
       "<IPython.core.display.HTML object>"
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    }
   ],
   "source": [
    "def reduce_outliers(x):\n",
    "    return min(np.log(1 + x), 4)\n",
    "\n",
    "steam_df_copy = steam_df.loc[steam_df['behavior-name'] == 'play'].copy()\n",
    "\n",
    "display(HTML(steam_df_copy.head(10).to_html()))\n",
    "\n",
    "steam_df_copy.loc[:, 'value'] = steam_df_copy['value'].apply(reduce_outliers)\n",
    "\n",
    "display(HTML(steam_df_copy.head(10).to_html()))"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "supported-graphic",
   "metadata": {},
   "source": [
    "### The same apply operation can be achieved with the use of a lambda function"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 56,
   "id": "objective-survey",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>user-id</th>\n",
       "      <th>game-title</th>\n",
       "      <th>behavior-name</th>\n",
       "      <th>value</th>\n",
       "      <th>zero</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>151603712</td>\n",
       "      <td>The Elder Scrolls V Skyrim</td>\n",
       "      <td>play</td>\n",
       "      <td>273.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>play</td>\n",
       "      <td>87.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>5</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Spore</td>\n",
       "      <td>play</td>\n",
       "      <td>14.9</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>7</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout New Vegas</td>\n",
       "      <td>play</td>\n",
       "      <td>12.1</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Left 4 Dead 2</td>\n",
       "      <td>play</td>\n",
       "      <td>8.9</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>11</th>\n",
       "      <td>151603712</td>\n",
       "      <td>HuniePop</td>\n",
       "      <td>play</td>\n",
       "      <td>8.5</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>13</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Path of Exile</td>\n",
       "      <td>play</td>\n",
       "      <td>8.1</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>15</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Poly Bridge</td>\n",
       "      <td>play</td>\n",
       "      <td>7.5</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>17</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Left 4 Dead</td>\n",
       "      <td>play</td>\n",
       "      <td>3.3</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>19</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Team Fortress 2</td>\n",
       "      <td>play</td>\n",
       "      <td>2.8</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>"
      ],
      "text/plain": [
       "<IPython.core.display.HTML object>"
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    },
    {
     "data": {
      "text/html": [
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>user-id</th>\n",
       "      <th>game-title</th>\n",
       "      <th>behavior-name</th>\n",
       "      <th>value</th>\n",
       "      <th>zero</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>151603712</td>\n",
       "      <td>The Elder Scrolls V Skyrim</td>\n",
       "      <td>play</td>\n",
       "      <td>4.000000</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>play</td>\n",
       "      <td>4.000000</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>5</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Spore</td>\n",
       "      <td>play</td>\n",
       "      <td>2.766319</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>7</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout New Vegas</td>\n",
       "      <td>play</td>\n",
       "      <td>2.572612</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Left 4 Dead 2</td>\n",
       "      <td>play</td>\n",
       "      <td>2.292535</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>11</th>\n",
       "      <td>151603712</td>\n",
       "      <td>HuniePop</td>\n",
       "      <td>play</td>\n",
       "      <td>2.251292</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>13</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Path of Exile</td>\n",
       "      <td>play</td>\n",
       "      <td>2.208274</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>15</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Poly Bridge</td>\n",
       "      <td>play</td>\n",
       "      <td>2.140066</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>17</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Left 4 Dead</td>\n",
       "      <td>play</td>\n",
       "      <td>1.458615</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>19</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Team Fortress 2</td>\n",
       "      <td>play</td>\n",
       "      <td>1.335001</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>"
      ],
      "text/plain": [
       "<IPython.core.display.HTML object>"
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    }
   ],
   "source": [
    "steam_df_copy = steam_df.loc[steam_df['behavior-name'] == 'play'].copy()\n",
    "\n",
    "display(HTML(steam_df_copy.head(10).to_html()))\n",
    "\n",
    "steam_df_copy.loc[:, 'value'] = steam_df_copy['value'].apply(lambda x: min(np.log(1 + x), 4))\n",
    "\n",
    "display(HTML(steam_df_copy.head(10).to_html()))"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "guilty-single",
   "metadata": {},
   "source": [
    "### Apply on two columns at once"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 58,
   "id": "thrown-geneva",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>user-id</th>\n",
       "      <th>game-title</th>\n",
       "      <th>behavior-name</th>\n",
       "      <th>value</th>\n",
       "      <th>zero</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>151603712</td>\n",
       "      <td>The Elder Scrolls V Skyrim</td>\n",
       "      <td>play</td>\n",
       "      <td>273.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>play</td>\n",
       "      <td>87.0</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>5</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Spore</td>\n",
       "      <td>play</td>\n",
       "      <td>14.9</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>7</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout New Vegas</td>\n",
       "      <td>play</td>\n",
       "      <td>12.1</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Left 4 Dead 2</td>\n",
       "      <td>play</td>\n",
       "      <td>8.9</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>11</th>\n",
       "      <td>151603712</td>\n",
       "      <td>HuniePop</td>\n",
       "      <td>play</td>\n",
       "      <td>8.5</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>13</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Path of Exile</td>\n",
       "      <td>play</td>\n",
       "      <td>8.1</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>15</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Poly Bridge</td>\n",
       "      <td>play</td>\n",
       "      <td>7.5</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>17</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Left 4 Dead</td>\n",
       "      <td>play</td>\n",
       "      <td>3.3</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>19</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Team Fortress 2</td>\n",
       "      <td>play</td>\n",
       "      <td>2.8</td>\n",
       "      <td>0</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>"
      ],
      "text/plain": [
       "<IPython.core.display.HTML object>"
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    },
    {
     "data": {
      "text/html": [
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>user-id</th>\n",
       "      <th>game-title</th>\n",
       "      <th>behavior-name</th>\n",
       "      <th>value</th>\n",
       "      <th>zero</th>\n",
       "      <th>value_2</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>151603712</td>\n",
       "      <td>The Elder Scrolls V Skyrim</td>\n",
       "      <td>play</td>\n",
       "      <td>273.0</td>\n",
       "      <td>0</td>\n",
       "      <td>4.000000</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>play</td>\n",
       "      <td>87.0</td>\n",
       "      <td>0</td>\n",
       "      <td>4.000000</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>5</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Spore</td>\n",
       "      <td>play</td>\n",
       "      <td>14.9</td>\n",
       "      <td>0</td>\n",
       "      <td>2.766319</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>7</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout New Vegas</td>\n",
       "      <td>play</td>\n",
       "      <td>12.1</td>\n",
       "      <td>0</td>\n",
       "      <td>2.572612</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Left 4 Dead 2</td>\n",
       "      <td>play</td>\n",
       "      <td>8.9</td>\n",
       "      <td>0</td>\n",
       "      <td>2.292535</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>11</th>\n",
       "      <td>151603712</td>\n",
       "      <td>HuniePop</td>\n",
       "      <td>play</td>\n",
       "      <td>8.5</td>\n",
       "      <td>0</td>\n",
       "      <td>2.251292</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>13</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Path of Exile</td>\n",
       "      <td>play</td>\n",
       "      <td>8.1</td>\n",
       "      <td>0</td>\n",
       "      <td>2.208274</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>15</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Poly Bridge</td>\n",
       "      <td>play</td>\n",
       "      <td>7.5</td>\n",
       "      <td>0</td>\n",
       "      <td>2.140066</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>17</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Left 4 Dead</td>\n",
       "      <td>play</td>\n",
       "      <td>3.3</td>\n",
       "      <td>0</td>\n",
       "      <td>1.458615</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>19</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Team Fortress 2</td>\n",
       "      <td>play</td>\n",
       "      <td>2.8</td>\n",
       "      <td>0</td>\n",
       "      <td>1.335001</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>"
      ],
      "text/plain": [
       "<IPython.core.display.HTML object>"
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    },
    {
     "data": {
      "text/html": [
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>user-id</th>\n",
       "      <th>game-title</th>\n",
       "      <th>behavior-name</th>\n",
       "      <th>value</th>\n",
       "      <th>zero</th>\n",
       "      <th>value_2</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>151603712</td>\n",
       "      <td>The Elder Scrolls V Skyrim</td>\n",
       "      <td>play</td>\n",
       "      <td>1092.000000</td>\n",
       "      <td>0</td>\n",
       "      <td>4.000000</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout 4</td>\n",
       "      <td>play</td>\n",
       "      <td>348.000000</td>\n",
       "      <td>0</td>\n",
       "      <td>4.000000</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>5</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Spore</td>\n",
       "      <td>play</td>\n",
       "      <td>41.218155</td>\n",
       "      <td>0</td>\n",
       "      <td>2.766319</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>7</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Fallout New Vegas</td>\n",
       "      <td>play</td>\n",
       "      <td>31.128608</td>\n",
       "      <td>0</td>\n",
       "      <td>2.572612</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Left 4 Dead 2</td>\n",
       "      <td>play</td>\n",
       "      <td>20.403559</td>\n",
       "      <td>0</td>\n",
       "      <td>2.292535</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>11</th>\n",
       "      <td>151603712</td>\n",
       "      <td>HuniePop</td>\n",
       "      <td>play</td>\n",
       "      <td>19.135980</td>\n",
       "      <td>0</td>\n",
       "      <td>2.251292</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>13</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Path of Exile</td>\n",
       "      <td>play</td>\n",
       "      <td>17.887023</td>\n",
       "      <td>0</td>\n",
       "      <td>2.208274</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>15</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Poly Bridge</td>\n",
       "      <td>play</td>\n",
       "      <td>16.050496</td>\n",
       "      <td>0</td>\n",
       "      <td>2.140066</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>17</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Left 4 Dead</td>\n",
       "      <td>play</td>\n",
       "      <td>4.813430</td>\n",
       "      <td>0</td>\n",
       "      <td>1.458615</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>19</th>\n",
       "      <td>151603712</td>\n",
       "      <td>Team Fortress 2</td>\n",
       "      <td>play</td>\n",
       "      <td>3.738003</td>\n",
       "      <td>0</td>\n",
       "      <td>1.335001</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>"
      ],
      "text/plain": [
       "<IPython.core.display.HTML object>"
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    }
   ],
   "source": [
    "steam_df_copy = steam_df.loc[steam_df['behavior-name'] == 'play'].copy()\n",
    "\n",
    "display(HTML(steam_df_copy.head(10).to_html()))\n",
    "\n",
    "steam_df_copy.loc[:, 'value_2'] = steam_df_copy['value'].apply(lambda x: min(np.log(1 + x), 4))\n",
    "\n",
    "display(HTML(steam_df_copy.head(10).to_html()))\n",
    "\n",
    "steam_df_copy.loc[:, 'value'] = steam_df_copy[['value', 'value_2']].apply(lambda x: x[0] * x[1], axis=1)\n",
    "\n",
    "display(HTML(steam_df_copy.head(10).to_html()))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 59,
   "id": "governing-alexandria",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>movieId</th>\n",
       "      <th>title</th>\n",
       "      <th>genres</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>0</th>\n",
       "      <td>1</td>\n",
       "      <td>Toy Story (1995)</td>\n",
       "      <td>Adventure|Animation|Children|Comedy|Fantasy</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>2</td>\n",
       "      <td>Jumanji (1995)</td>\n",
       "      <td>Adventure|Children|Fantasy</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2</th>\n",
       "      <td>3</td>\n",
       "      <td>Grumpier Old Men (1995)</td>\n",
       "      <td>Comedy|Romance</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>4</td>\n",
       "      <td>Waiting to Exhale (1995)</td>\n",
       "      <td>Comedy|Drama|Romance</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>4</th>\n",
       "      <td>5</td>\n",
       "      <td>Father of the Bride Part II (1995)</td>\n",
       "      <td>Comedy</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>5</th>\n",
       "      <td>6</td>\n",
       "      <td>Heat (1995)</td>\n",
       "      <td>Action|Crime|Thriller</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>6</th>\n",
       "      <td>7</td>\n",
       "      <td>Sabrina (1995)</td>\n",
       "      <td>Comedy|Romance</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>7</th>\n",
       "      <td>8</td>\n",
       "      <td>Tom and Huck (1995)</td>\n",
       "      <td>Adventure|Children</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>8</th>\n",
       "      <td>9</td>\n",
       "      <td>Sudden Death (1995)</td>\n",
       "      <td>Action</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9</th>\n",
       "      <td>10</td>\n",
       "      <td>GoldenEye (1995)</td>\n",
       "      <td>Action|Adventure|Thriller</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>"
      ],
      "text/plain": [
       "<IPython.core.display.HTML object>"
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    },
    {
     "data": {
      "text/html": [
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>movieId</th>\n",
       "      <th>title</th>\n",
       "      <th>genres</th>\n",
       "      <th>title|genres</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>0</th>\n",
       "      <td>1</td>\n",
       "      <td>Toy Story (1995)</td>\n",
       "      <td>Adventure|Animation|Children|Comedy|Fantasy</td>\n",
       "      <td>Toy Story (1995)|Adventure|Animation|Children|Comedy|Fantasy</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>2</td>\n",
       "      <td>Jumanji (1995)</td>\n",
       "      <td>Adventure|Children|Fantasy</td>\n",
       "      <td>Jumanji (1995)|Adventure|Children|Fantasy</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2</th>\n",
       "      <td>3</td>\n",
       "      <td>Grumpier Old Men (1995)</td>\n",
       "      <td>Comedy|Romance</td>\n",
       "      <td>Grumpier Old Men (1995)|Comedy|Romance</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>4</td>\n",
       "      <td>Waiting to Exhale (1995)</td>\n",
       "      <td>Comedy|Drama|Romance</td>\n",
       "      <td>Waiting to Exhale (1995)|Comedy|Drama|Romance</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>4</th>\n",
       "      <td>5</td>\n",
       "      <td>Father of the Bride Part II (1995)</td>\n",
       "      <td>Comedy</td>\n",
       "      <td>Father of the Bride Part II (1995)|Comedy</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>5</th>\n",
       "      <td>6</td>\n",
       "      <td>Heat (1995)</td>\n",
       "      <td>Action|Crime|Thriller</td>\n",
       "      <td>Heat (1995)|Action|Crime|Thriller</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>6</th>\n",
       "      <td>7</td>\n",
       "      <td>Sabrina (1995)</td>\n",
       "      <td>Comedy|Romance</td>\n",
       "      <td>Sabrina (1995)|Comedy|Romance</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>7</th>\n",
       "      <td>8</td>\n",
       "      <td>Tom and Huck (1995)</td>\n",
       "      <td>Adventure|Children</td>\n",
       "      <td>Tom and Huck (1995)|Adventure|Children</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>8</th>\n",
       "      <td>9</td>\n",
       "      <td>Sudden Death (1995)</td>\n",
       "      <td>Action</td>\n",
       "      <td>Sudden Death (1995)|Action</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9</th>\n",
       "      <td>10</td>\n",
       "      <td>GoldenEye (1995)</td>\n",
       "      <td>Action|Adventure|Thriller</td>\n",
       "      <td>GoldenEye (1995)|Action|Adventure|Thriller</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>"
      ],
      "text/plain": [
       "<IPython.core.display.HTML object>"
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    }
   ],
   "source": [
    "ml_movies_df_copy = ml_movies_df.copy()\n",
    "\n",
    "display(HTML(ml_movies_df_copy.head(10).to_html()))\n",
    "\n",
    "ml_movies_df_copy.loc[:, 'title|genres'] = ml_movies_df_copy[['title', 'genres']].apply(lambda x: x[0] + \"|\" + x[1], axis=1)\n",
    "\n",
    "display(HTML(ml_movies_df_copy.head(10).to_html()))"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "critical-fields",
   "metadata": {},
   "source": [
    "## Grouping and aggregating"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "biological-light",
   "metadata": {},
   "source": [
    "### Find the most popular games (in terms of purchases)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 61,
   "id": "greenhouse-scout",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>value</th>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>game-title</th>\n",
       "      <th></th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>007 Legends</th>\n",
       "      <td>1.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>0RBITALIS</th>\n",
       "      <td>3.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1... 2... 3... KICK IT! (Drop That Beat Like an Ugly Baby)</th>\n",
       "      <td>7.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>10 Second Ninja</th>\n",
       "      <td>6.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>10,000,000</th>\n",
       "      <td>1.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>100% Orange Juice</th>\n",
       "      <td>10.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1000 Amps</th>\n",
       "      <td>2.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>12 Labours of Hercules</th>\n",
       "      <td>10.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>12 Labours of Hercules II The Cretan Bull</th>\n",
       "      <td>12.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>12 Labours of Hercules III Girl Power</th>\n",
       "      <td>6.0</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>"
      ],
      "text/plain": [
       "<IPython.core.display.HTML object>"
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    },
    {
     "data": {
      "text/html": [
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>game-title</th>\n",
       "      <th>value</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>0</th>\n",
       "      <td>Dota 2</td>\n",
       "      <td>4841.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>Team Fortress 2</td>\n",
       "      <td>2323.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2</th>\n",
       "      <td>Unturned</td>\n",
       "      <td>1563.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>Counter-Strike Global Offensive</td>\n",
       "      <td>1412.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>4</th>\n",
       "      <td>Half-Life 2 Lost Coast</td>\n",
       "      <td>981.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>5</th>\n",
       "      <td>Counter-Strike Source</td>\n",
       "      <td>978.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>6</th>\n",
       "      <td>Left 4 Dead 2</td>\n",
       "      <td>951.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>7</th>\n",
       "      <td>Counter-Strike</td>\n",
       "      <td>856.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>8</th>\n",
       "      <td>Warframe</td>\n",
       "      <td>847.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9</th>\n",
       "      <td>Half-Life 2 Deathmatch</td>\n",
       "      <td>823.0</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>"
      ],
      "text/plain": [
       "<IPython.core.display.HTML object>"
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    }
   ],
   "source": [
    "steam_grouped = steam_df.loc[steam_df['behavior-name'] == 'purchase', ['game-title', 'value']]\n",
    "steam_grouped = steam_grouped.groupby('game-title').sum()\n",
    "display(HTML(steam_grouped.head(10).to_html()))\n",
    "\n",
    "steam_grouped = steam_grouped.sort_values(by='value', ascending=False).reset_index()\n",
    "\n",
    "display(HTML(steam_grouped.head(10).to_html()))"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "indie-calcium",
   "metadata": {},
   "source": [
    "## Iterating over a DataFrame (if possible, use column operations instead)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 63,
   "id": "laden-intersection",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "[0, 151603712, The Elder Scrolls V Skyrim, purchase]\n",
      "[1, 151603712, The Elder Scrolls V Skyrim, play]\n",
      "[2, 151603712, Fallout 4, purchase]\n",
      "[3, 151603712, Fallout 4, play]\n",
      "[4, 151603712, Spore, purchase]\n",
      "[5, 151603712, Spore, play]\n",
      "[6, 151603712, Fallout New Vegas, purchase]\n",
      "[7, 151603712, Fallout New Vegas, play]\n",
      "[8, 151603712, Left 4 Dead 2, purchase]\n",
      "[9, 151603712, Left 4 Dead 2, play]\n"
     ]
    }
   ],
   "source": [
    "i = 0\n",
    "for idx, row in steam_df.iterrows():\n",
    "    print(\"[{}, {}, {}, {}]\".format(idx, row['user-id'], row['game-title'], row['behavior-name']))\n",
    "    i += 1\n",
    "    if i == 10:\n",
    "        break"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "objective-associate",
   "metadata": {},
   "source": [
    "## Pandas tasks - Steam dataset"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "floppy-american",
   "metadata": {},
   "source": [
    "**Task 4.** How many people made a purchase in the Steam dataset? Remember that a person could by many games, but you need to count every person once."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "decimal-grass",
   "metadata": {},
   "outputs": [],
   "source": [
    "# Write your code here"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "protected-glossary",
   "metadata": {},
   "source": [
    "**Task 5.** How many people made a purchase of \"The Elder Scrolls V Skyrim\"?"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "distant-overview",
   "metadata": {},
   "outputs": [],
   "source": [
    "# Write your code here"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "vocational-weekly",
   "metadata": {},
   "source": [
    "**Task 6.** How many purchases people made on average?"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "reflected-cathedral",
   "metadata": {},
   "outputs": [],
   "source": [
    "# Write your code here"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "signed-transaction",
   "metadata": {},
   "source": [
    "**Task 7.** Who bought the most games?"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "handmade-revolution",
   "metadata": {},
   "outputs": [],
   "source": [
    "# Write your code here"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "piano-bobby",
   "metadata": {},
   "source": [
    "**Task 8.** How many hours on average people played in \"The Elder Scrolls V Skyrim\"?"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "hydraulic-observation",
   "metadata": {},
   "outputs": [],
   "source": [
    "# Write your code here"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "stuffed-creativity",
   "metadata": {},
   "source": [
    "**Task 9.** Which games were played the most (in terms of the number of hours played)? Print the first 10 titles and respective numbers of hours."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "challenging-truck",
   "metadata": {},
   "outputs": [],
   "source": [
    "# Write your code here"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "crude-petroleum",
   "metadata": {},
   "source": [
    "**Task 10.** Which games are the most consistently played (in terms of the average number of hours played)? Print the first 10 titles and respective numbers of hours."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "surgical-lawsuit",
   "metadata": {},
   "outputs": [],
   "source": [
    "# Write your code here"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "monetary-toyota",
   "metadata": {},
   "source": [
    "**Task 11\\*\\*.** Fix the above for the fact that 0 hours played is not listed, but only a purchase is recorded in such a case."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "protective-report",
   "metadata": {},
   "outputs": [],
   "source": [
    "# Write your code here"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "ceramic-awareness",
   "metadata": {},
   "source": [
    "**Task 12.** Apply the sigmoid function\n",
    "$$f(x) = \\frac{1}{1 + e^{-\\frac{1}{100}x}}$$\n",
    "to hours played and print the first 10 rows from the entire Steam dataset after this change."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "optical-announcement",
   "metadata": {},
   "outputs": [],
   "source": [
    "# Write your code here"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "actual-spotlight",
   "metadata": {},
   "source": [
    "## Pandas tasks - MovieLens dataset"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "inclusive-crash",
   "metadata": {},
   "source": [
    "**Task 13\\*.** Calculate popularity (by the number of users who watched a movie) of all genres."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "developmental-seven",
   "metadata": {},
   "outputs": [],
   "source": [
    "# Write your code here"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "personalized-finland",
   "metadata": {},
   "source": [
    "**Task 14\\*.** Calculate average rating for all genres."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "inside-personal",
   "metadata": {},
   "outputs": [],
   "source": [
    "# Write your code here"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "vertical-stick",
   "metadata": {},
   "source": [
    "**Task 15.** Calculate each movie rating bias (deviation from the mean of all movies average ratings). Print first 10 in the form: title, average rating, bias."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "greatest-screen",
   "metadata": {},
   "outputs": [],
   "source": [
    "# Write your code here"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "hawaiian-haiti",
   "metadata": {},
   "source": [
    "**Task 16.** Calculate each user rating bias (deviation from the mean of all users average ratings). Print first 10 in the form: user_id, average rating, bias."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "charitable-guyana",
   "metadata": {},
   "outputs": [],
   "source": [
    "# Write your code here"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "intimate-porcelain",
   "metadata": {},
   "source": [
    "**Task 17.** Randomly choose 10 movies and 10 users and print their interaction matrix in the form of a DataFrame with user_id as index and movie titles as columns (use HTML Display for that). You can iterate over the DataFrame in this task."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "brazilian-frost",
   "metadata": {},
   "outputs": [],
   "source": [
    "# Write your code here"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "boolean-modem",
   "metadata": {},
   "source": [
    "## Pandas + numpy tasks"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "worldwide-disclaimer",
   "metadata": {},
   "source": [
    "**Task 18.** Create the entire interaction matrix for the MovieLens dataset."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "marine-initial",
   "metadata": {},
   "outputs": [],
   "source": [
    "# Write your code here"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "micro-vision",
   "metadata": {},
   "source": [
    "**Task 19.** Calculate the matrix of size (n_users, n_users) where at position (i, j) is the number of movies watched both by user i and user j. Print the submatrix of first 10 rows and 10 columns."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "swedish-lambda",
   "metadata": {},
   "outputs": [],
   "source": [
    "# Write your code here"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "shaped-advance",
   "metadata": {},
   "source": [
    "**Task 20.** Calculate the matrix of size (n_items, n_items) where at position (i, j) is the number of users who watched both movie i and movie j. Print the submatrix of first 10 rows and 10 columns."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "quality-bubble",
   "metadata": {},
   "outputs": [],
   "source": [
    "# Write your code here"
   ]
  }
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