|
| 1 | +{ |
| 2 | + "cells": [ |
| 3 | + { |
| 4 | + "cell_type": "markdown", |
| 5 | + "metadata": { |
| 6 | + "id": "KYoVrnewenmh" |
| 7 | + }, |
| 8 | + "source": [ |
| 9 | + "### Bag of words: Exercises\n", |
| 10 | + "\n", |
| 11 | + "\n", |
| 12 | + "- In this Exercise, you are going to classify whether a given movie review is **positive or negative**.\n", |
| 13 | + "- you are going to use Bag of words for pre-processing the text and apply different classification algorithms.\n", |
| 14 | + "- Sklearn CountVectorizer has the inbuilt implementations for Bag of Words." |
| 15 | + ] |
| 16 | + }, |
| 17 | + { |
| 18 | + "cell_type": "code", |
| 19 | + "execution_count": 24, |
| 20 | + "metadata": { |
| 21 | + "id": "JW6MPIjib_4G" |
| 22 | + }, |
| 23 | + "outputs": [], |
| 24 | + "source": [ |
| 25 | + "#Import necessary libraries\n", |
| 26 | + "\n", |
| 27 | + "import pandas as pd\n", |
| 28 | + "import numpy as np\n", |
| 29 | + "from sklearn.model_selection import train_test_split\n", |
| 30 | + "from sklearn.feature_extraction.text import CountVectorizer\n", |
| 31 | + "from sklearn.ensemble import RandomForestClassifier\n", |
| 32 | + "from sklearn.neighbors import KNeighborsClassifier\n", |
| 33 | + "from sklearn.naive_bayes import MultinomialNB\n", |
| 34 | + "from sklearn.pipeline import Pipeline\n", |
| 35 | + "from sklearn.metrics import classification_report" |
| 36 | + ] |
| 37 | + }, |
| 38 | + { |
| 39 | + "cell_type": "markdown", |
| 40 | + "metadata": { |
| 41 | + "id": "kDATDCL8NMML" |
| 42 | + }, |
| 43 | + "source": [ |
| 44 | + "### **About Data: IMDB Dataset**\n", |
| 45 | + "\n", |
| 46 | + "Credits: https://www.kaggle.com/datasets/lakshmi25npathi/imdb-dataset-of-50k-movie-reviews?resource=download\n", |
| 47 | + "\n", |
| 48 | + "\n", |
| 49 | + "- This data consists of two columns.\n", |
| 50 | + " - review\n", |
| 51 | + " - sentiment\n", |
| 52 | + "- Reviews are the statements given by users after watching the movie.\n", |
| 53 | + "- sentiment feature tells whether the given review is positive or negative." |
| 54 | + ] |
| 55 | + }, |
| 56 | + { |
| 57 | + "cell_type": "code", |
| 58 | + "execution_count": 1, |
| 59 | + "metadata": { |
| 60 | + "colab": { |
| 61 | + "base_uri": "https://localhost:8080/", |
| 62 | + "height": 224 |
| 63 | + }, |
| 64 | + "id": "beL29JwEb_7O", |
| 65 | + "outputId": "cf0a9e1e-b80b-4447-d759-0828baba2620" |
| 66 | + }, |
| 67 | + "outputs": [], |
| 68 | + "source": [ |
| 69 | + "#1. read the data provided in the same directory with name 'movies_sentiment_data.csv' and store it in df variable\n", |
| 70 | + "\n", |
| 71 | + "\n", |
| 72 | + "\n", |
| 73 | + "#2. print the shape of the data\n", |
| 74 | + "\n", |
| 75 | + "\n", |
| 76 | + "#3. print top 5 datapoints\n" |
| 77 | + ] |
| 78 | + }, |
| 79 | + { |
| 80 | + "cell_type": "code", |
| 81 | + "execution_count": 26, |
| 82 | + "metadata": {}, |
| 83 | + "outputs": [], |
| 84 | + "source": [ |
| 85 | + "#creating a new column \"Category\" which represent 1 if the sentiment is positive or 0 if it is negative\n" |
| 86 | + ] |
| 87 | + }, |
| 88 | + { |
| 89 | + "cell_type": "code", |
| 90 | + "execution_count": 2, |
| 91 | + "metadata": { |
| 92 | + "colab": { |
| 93 | + "base_uri": "https://localhost:8080/" |
| 94 | + }, |
| 95 | + "id": "OSwPM7mub_9S", |
| 96 | + "outputId": "2b68719c-b7f4-48b8-a41e-3f95cca9f2f2" |
| 97 | + }, |
| 98 | + "outputs": [], |
| 99 | + "source": [ |
| 100 | + "#check the distribution of 'Category' and see whether the Target labels are balanced or not.\n", |
| 101 | + "\n" |
| 102 | + ] |
| 103 | + }, |
| 104 | + { |
| 105 | + "cell_type": "code", |
| 106 | + "execution_count": 3, |
| 107 | + "metadata": { |
| 108 | + "id": "IB97QiFCcAAe" |
| 109 | + }, |
| 110 | + "outputs": [], |
| 111 | + "source": [ |
| 112 | + "#Do the 'train-test' splitting with test size of 20%\n", |
| 113 | + "\n" |
| 114 | + ] |
| 115 | + }, |
| 116 | + { |
| 117 | + "cell_type": "code", |
| 118 | + "execution_count": null, |
| 119 | + "metadata": { |
| 120 | + "id": "mtr4mSLEMWiU" |
| 121 | + }, |
| 122 | + "outputs": [], |
| 123 | + "source": [] |
| 124 | + }, |
| 125 | + { |
| 126 | + "cell_type": "markdown", |
| 127 | + "metadata": { |
| 128 | + "id": "J-pUGPqwMrDQ" |
| 129 | + }, |
| 130 | + "source": [ |
| 131 | + "**Exercise-1**\n", |
| 132 | + "\n", |
| 133 | + "1. using sklearn pipeline module create a classification pipeline to classify the movie review's positive or negative.\n", |
| 134 | + "\n", |
| 135 | + "**Note:**\n", |
| 136 | + "- use CountVectorizer for pre-processing the text.\n", |
| 137 | + "\n", |
| 138 | + "- use **Random Forest** as the classifier with estimators as 50 and criterion as entropy.\n", |
| 139 | + "- print the classification report.\n", |
| 140 | + "\n", |
| 141 | + "**References**:\n", |
| 142 | + "\n", |
| 143 | + "- https://scikit-learn.org/stable/modules/generated/sklearn.ensemble.RandomForestClassifier.html\n", |
| 144 | + "\n", |
| 145 | + "- https://scikit-learn.org/stable/modules/generated/sklearn.feature_extraction.text.CountVectorizer.html" |
| 146 | + ] |
| 147 | + }, |
| 148 | + { |
| 149 | + "cell_type": "code", |
| 150 | + "execution_count": 4, |
| 151 | + "metadata": { |
| 152 | + "colab": { |
| 153 | + "base_uri": "https://localhost:8080/" |
| 154 | + }, |
| 155 | + "id": "CbldZv03MWkB", |
| 156 | + "outputId": "cf70d361-da12-46a9-8d59-73cdba9bad91" |
| 157 | + }, |
| 158 | + "outputs": [], |
| 159 | + "source": [ |
| 160 | + "#1. create a pipeline object\n", |
| 161 | + "\n", |
| 162 | + "\n", |
| 163 | + "\n", |
| 164 | + "\n", |
| 165 | + "#2. fit with X_train and y_train\n", |
| 166 | + "\n", |
| 167 | + "\n", |
| 168 | + "\n", |
| 169 | + "#3. get the predictions for X_test and store it in y_pred\n", |
| 170 | + "\n", |
| 171 | + "\n", |
| 172 | + "\n", |
| 173 | + "#4. print the classfication report\n" |
| 174 | + ] |
| 175 | + }, |
| 176 | + { |
| 177 | + "cell_type": "markdown", |
| 178 | + "metadata": { |
| 179 | + "id": "WMVvGzqXSFYr" |
| 180 | + }, |
| 181 | + "source": [ |
| 182 | + "**Exercise-2**\n", |
| 183 | + "\n", |
| 184 | + "1. using sklearn pipeline module create a classification pipeline to classify the movie review's positive or negative..\n", |
| 185 | + "\n", |
| 186 | + "**Note:**\n", |
| 187 | + "- use CountVectorizer for pre-processing the text.\n", |
| 188 | + "- use **KNN** as the classifier with n_neighbors of 10 and metric as 'euclidean'.\n", |
| 189 | + "- print the classification report.\n", |
| 190 | + "\n", |
| 191 | + "**References**:\n", |
| 192 | + "\n", |
| 193 | + "- https://scikit-learn.org/stable/modules/generated/sklearn.feature_extraction.text.CountVectorizer.html\n", |
| 194 | + "- https://scikit-learn.org/stable/modules/generated/sklearn.neighbors.KNeighborsClassifier.html\n", |
| 195 | + "\n" |
| 196 | + ] |
| 197 | + }, |
| 198 | + { |
| 199 | + "cell_type": "code", |
| 200 | + "execution_count": 5, |
| 201 | + "metadata": { |
| 202 | + "colab": { |
| 203 | + "base_uri": "https://localhost:8080/" |
| 204 | + }, |
| 205 | + "id": "tYkY77S6MWng", |
| 206 | + "outputId": "53275bdc-4629-464c-d26f-00075b080174" |
| 207 | + }, |
| 208 | + "outputs": [], |
| 209 | + "source": [ |
| 210 | + "\n", |
| 211 | + "#1. create a pipeline object\n", |
| 212 | + "\n", |
| 213 | + "\n", |
| 214 | + "#2. fit with X_train and y_train\n", |
| 215 | + "\n", |
| 216 | + "\n", |
| 217 | + "\n", |
| 218 | + "#3. get the predictions for X_test and store it in y_pred\n", |
| 219 | + "\n", |
| 220 | + "\n", |
| 221 | + "#4. print the classfication report\n" |
| 222 | + ] |
| 223 | + }, |
| 224 | + { |
| 225 | + "cell_type": "markdown", |
| 226 | + "metadata": {}, |
| 227 | + "source": [ |
| 228 | + "**Exercise-3**\n", |
| 229 | + "\n", |
| 230 | + "1. using sklearn pipeline module create a classification pipeline to classify the movie review's positive or negative..\n", |
| 231 | + "\n", |
| 232 | + "**Note:**\n", |
| 233 | + "- use CountVectorizer for pre-processing the text.\n", |
| 234 | + "- use **Multinomial Naive Bayes** as the classifier.\n", |
| 235 | + "- print the classification report.\n", |
| 236 | + "\n", |
| 237 | + "**References**:\n", |
| 238 | + "\n", |
| 239 | + "- https://scikit-learn.org/stable/modules/generated/sklearn.feature_extraction.text.CountVectorizer.html\n", |
| 240 | + "- https://scikit-learn.org/stable/modules/generated/sklearn.naive_bayes.MultinomialNB.html\n", |
| 241 | + "\n" |
| 242 | + ] |
| 243 | + }, |
| 244 | + { |
| 245 | + "cell_type": "code", |
| 246 | + "execution_count": 6, |
| 247 | + "metadata": {}, |
| 248 | + "outputs": [], |
| 249 | + "source": [ |
| 250 | + "\n", |
| 251 | + "#1. create a pipeline object\n", |
| 252 | + "\n", |
| 253 | + "\n", |
| 254 | + "\n", |
| 255 | + "#2. fit with X_train and y_train\n", |
| 256 | + "\n", |
| 257 | + "\n", |
| 258 | + "\n", |
| 259 | + "#3. get the predictions for X_test and store it in y_pred\n", |
| 260 | + "\n", |
| 261 | + "\n", |
| 262 | + "\n", |
| 263 | + "#4. print the classfication report\n" |
| 264 | + ] |
| 265 | + }, |
| 266 | + { |
| 267 | + "cell_type": "code", |
| 268 | + "execution_count": null, |
| 269 | + "metadata": {}, |
| 270 | + "outputs": [], |
| 271 | + "source": [] |
| 272 | + }, |
| 273 | + { |
| 274 | + "cell_type": "markdown", |
| 275 | + "metadata": {}, |
| 276 | + "source": [ |
| 277 | + "### Can you write some observations of why model like KNN fails to produce good results unlike RandomForest and MultinomialNB?\n", |
| 278 | + "\n" |
| 279 | + ] |
| 280 | + }, |
| 281 | + { |
| 282 | + "cell_type": "markdown", |
| 283 | + "metadata": {}, |
| 284 | + "source": [ |
| 285 | + "## [**Solution**](./bag_of_words_exercise_solutions.ipynb)" |
| 286 | + ] |
| 287 | + } |
| 288 | + ], |
| 289 | + "metadata": { |
| 290 | + "colab": { |
| 291 | + "collapsed_sections": [], |
| 292 | + "name": "BOW_exercise.ipynb", |
| 293 | + "provenance": [] |
| 294 | + }, |
| 295 | + "kernelspec": { |
| 296 | + "display_name": "Python 3 (ipykernel)", |
| 297 | + "language": "python", |
| 298 | + "name": "python3" |
| 299 | + }, |
| 300 | + "language_info": { |
| 301 | + "codemirror_mode": { |
| 302 | + "name": "ipython", |
| 303 | + "version": 3 |
| 304 | + }, |
| 305 | + "file_extension": ".py", |
| 306 | + "mimetype": "text/x-python", |
| 307 | + "name": "python", |
| 308 | + "nbconvert_exporter": "python", |
| 309 | + "pygments_lexer": "ipython3", |
| 310 | + "version": "3.8.10" |
| 311 | + } |
| 312 | + }, |
| 313 | + "nbformat": 4, |
| 314 | + "nbformat_minor": 1 |
| 315 | +} |
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