MLJourney
Day 20
Week 3

NLP with Scikit-learn: Getting Started with Text Data

Overview

Natural Language Processing (NLP) allows machines to understand and interpret human language. Scikit-learn provides powerful tools for handling basic NLP tasks like text classification, vectorization, and sentiment analysis.

Today, you'll explore how to clean text, convert it into numerical representations using techniques like Bag-of-Words and TF-IDF, and build classification models on text data using Scikit-learn.

Key Concepts
  • Text preprocessing: tokenization, stopwords, stemming
  • Bag-of-Words & TF-IDF Vectorization
  • Using <code>CountVectorizer</code> and <code>TfidfVectorizer</code>
  • Naive Bayes and Logistic Regression for text classification
  • Evaluating NLP models with accuracy, precision, recall
Practice Exercise

Exercise: Spam Detection with NLP

  1. Load a dataset like the SMS Spam Collection dataset from UCI or Kaggle.
  2. Preprocess the text: lowercase, remove punctuation, stopwords, and apply stemming.
  3. Use CountVectorizer and TfidfVectorizer to convert text into features.
  4. Train a MultinomialNB and LogisticRegression model.
  5. Evaluate with a confusion matrix and classification report.
  6. Compare the effect of BoW vs TF-IDF on model performance.
Resources

Kaggle NLP Course

Main resource for today

Scikit-learn Text Feature Extraction

Official documentation for text feature extraction in Scikit-learn

Text Classification with Scikit-learn

Tutorial on building and evaluating text classifiers

SMS Spam Classifier Notebook

Example notebook for spam detection using Scikit-learn

Complete Today's Task

Mark today's task as complete to track your progress and earn achievements.