File size: 5,966 Bytes
854c114
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
{
    "cells": [
        {
            "cell_type": "markdown",
            "metadata": {},
            "source": [
                "# ML Practice Series: Module 19 - Natural Language Processing (NLP)\n",
                "\n",
                "Welcome to Module 19! **Natural Language Processing** allows machines to understand, interpret, and generate human language. This is the tech behind Siri, Google Translate, and ChatGPT.\n",
                "\n",
                "### Objectives:\n",
                "1. **Text Cleaning**: Removing punctuation and stopwords.\n",
                "2. **Tokenization & Lemmatization**: Breaking down words to their roots.\n",
                "3. **TF-IDF**: Weighing word importance in a document.\n",
                "4. **Sentiment Analysis**: Predicting if a text is positive or negative.\n",
                "\n",
                "---"
            ]
        },
        {
            "cell_type": "markdown",
            "metadata": {},
            "source": [
                "## 1. Setup\n",
                "We will use a dataset of movie reviews to perform sentiment analysis."
            ]
        },
        {
            "cell_type": "code",
            "execution_count": null,
            "metadata": {},
            "outputs": [],
            "source": [
                "import pandas as pd\n",
                "import numpy as np\n",
                "from sklearn.model_selection import train_test_split\n",
                "from sklearn.feature_extraction.text import TfidfVectorizer\n",
                "from sklearn.linear_model import LogisticRegression\n",
                "from sklearn.metrics import accuracy_score\n",
                "\n",
                "# Sample Dataset\n",
                "reviews = [\n",
                "    (\"I loved this movie! The acting was great.\", 1),\n",
                "    (\"Terrible film, a complete waste of time.\", 0),\n",
                "    (\"The plot was boring but the music was okay.\", 0),\n",
                "    (\"Truly a masterpiece of cinema.\", 1),\n",
                "    (\"I would not recommend this to anybody.\", 0),\n",
                "    (\"Best experience I have had in a theater.\", 1)\n",
                "]\n",
                "df = pd.DataFrame(reviews, columns=['text', 'sentiment'])\n",
                "df"
            ]
        },
        {
            "cell_type": "markdown",
            "metadata": {},
            "source": [
                "## 2. Text Transformation\n",
                "\n",
                "### Task 1: TF-IDF Vectorization\n",
                "Convert the text reviews into a numerical matrix using `TfidfVectorizer` (Term Frequency-Inverse Document Frequency).\n",
                "\n",
                "*Web Reference: [ML Guide - NLP Section](https://aashishgarg13.github.io/DataScience/ml_complete-all-topics/)*"
            ]
        },
        {
            "cell_type": "code",
            "execution_count": null,
            "metadata": {},
            "outputs": [],
            "source": [
                "# YOUR CODE HERE\n"
            ]
        },
        {
            "cell_type": "markdown",
            "metadata": {},
            "source": [
                "<details>\n",
                "<summary><b>Click to see Solution</b></summary>\n",
                "\n",
                "```python\n",
                "tfidf = TfidfVectorizer(stop_words='english')\n",
                "X = tfidf.fit_transform(df['text'])\n",
                "y = df['sentiment']\n",
                "print(\"Feature names:\", tfidf.get_feature_names_out()[:10])\n",
                "```\n",
                "</details>"
            ]
        },
        {
            "cell_type": "markdown",
            "metadata": {},
            "source": [
                "## 3. Sentiment Classification\n",
                "\n",
                "### Task 2: Training the Classifier\n",
                "Train a `LogisticRegression` model on the TF-IDF matrix and predict the sentiment of: \"This was a really fun movie!\""
            ]
        },
        {
            "cell_type": "code",
            "execution_count": null,
            "metadata": {},
            "outputs": [],
            "source": [
                "# YOUR CODE HERE\n"
            ]
        },
        {
            "cell_type": "markdown",
            "metadata": {},
            "source": [
                "<details>\n",
                "<summary><b>Click to see Solution</b></summary>\n",
                "\n",
                "```python\n",
                "model = LogisticRegression()\n",
                "model.fit(X, y)\n",
                "\n",
                "new_review = [\"This was a really fun movie!\"]\n",
                "new_vec = tfidf.transform(new_review)\n",
                "pred = model.predict(new_vec)\n",
                "\n",
                "print(\"Positive\" if pred[0] == 1 else \"Negative\")\n",
                "```\n",
                "</details>"
            ]
        },
        {
            "cell_type": "markdown",
            "metadata": {},
            "source": [
                "--- \n",
                "### NLP Mission Accomplished! \n",
                "You've learned how to turn human language into math. \n",
                "This is your final module in the core series!"
            ]
        }
    ],
    "metadata": {
        "kernelspec": {
            "display_name": "Python 3",
            "language": "python",
            "name": "python3"
        },
        "language_info": {
            "codemirror_mode": {
                "name": "ipython",
                "version": 3
            },
            "file_extension": ".py",
            "mimetype": "text/x-python",
            "name": "python",
            "nbconvert_exporter": "python",
            "pygments_lexer": "ipython3",
            "version": "3.12.7"
        }
    },
    "nbformat": 4,
    "nbformat_minor": 4
}