Book Image

Python Data Analysis - Third Edition

By : Avinash Navlani, Ivan Idris
5 (1)
Book Image

Python Data Analysis - Third Edition

5 (1)
By: Avinash Navlani, Ivan Idris

Overview of this book

Data analysis enables you to generate value from small and big data by discovering new patterns and trends, and Python is one of the most popular tools for analyzing a wide variety of data. With this book, you’ll get up and running using Python for data analysis by exploring the different phases and methodologies used in data analysis and learning how to use modern libraries from the Python ecosystem to create efficient data pipelines. Starting with the essential statistical and data analysis fundamentals using Python, you’ll perform complex data analysis and modeling, data manipulation, data cleaning, and data visualization using easy-to-follow examples. You’ll then understand how to conduct time series analysis and signal processing using ARMA models. As you advance, you’ll get to grips with smart processing and data analytics using machine learning algorithms such as regression, classification, Principal Component Analysis (PCA), and clustering. In the concluding chapters, you’ll work on real-world examples to analyze textual and image data using natural language processing (NLP) and image analytics techniques, respectively. Finally, the book will demonstrate parallel computing using Dask. By the end of this data analysis book, you’ll be equipped with the skills you need to prepare data for analysis and create meaningful data visualizations for forecasting values from data.
Table of Contents (20 chapters)
1
Section 1: Foundation for Data Analysis
6
Section 2: Exploratory Data Analysis and Data Cleaning
11
Section 3: Deep Dive into Machine Learning
15
Section 4: NLP, Image Analytics, and Parallel Computing

Removing stopwords

Stopwords are counted as noise in text analysis. Any text paragraph has to have verbs, articles, and propositions. These are all considered stop words. Stop words are necessary for human conversation but they don't make many contributions in text analysis. Removing stopwords from text is called noise elimination.

Let's see how to remove stopwords using NLTK:

# import the nltk stopwords
from nltk.corpus import stopwords

# Load english stopwords list
stopwords_set=set(stopwords.words("english"))

# Removing stopwords from text
filtered_word_list=[]
for word in tokenized_words:
# filter stopwords
if word not in stopwords_set:
filtered_word_list.append(word)

# print tokenized words
print("Tokenized Word List:", tokenized_words)

# print filtered words
print("Filtered Word List:", filtered_word_list)

This results in the following output:

Tokenized Word List: ['Taj', 'Mahal', 'is', 'one', &apos...