Book Image

The Data Science Workshop - Second Edition

By : Anthony So, Thomas V. Joseph, Robert Thas John, Andrew Worsley, Dr. Samuel Asare
5 (1)
Book Image

The Data Science Workshop - Second Edition

5 (1)
By: Anthony So, Thomas V. Joseph, Robert Thas John, Andrew Worsley, Dr. Samuel Asare

Overview of this book

Where there’s data, there’s insight. With so much data being generated, there is immense scope to extract meaningful information that’ll boost business productivity and profitability. By learning to convert raw data into game-changing insights, you’ll open new career paths and opportunities. The Data Science Workshop begins by introducing different types of projects and showing you how to incorporate machine learning algorithms in them. You’ll learn to select a relevant metric and even assess the performance of your model. To tune the hyperparameters of an algorithm and improve its accuracy, you’ll get hands-on with approaches such as grid search and random search. Next, you’ll learn dimensionality reduction techniques to easily handle many variables at once, before exploring how to use model ensembling techniques and create new features to enhance model performance. In a bid to help you automatically create new features that improve your model, the book demonstrates how to use the automated feature engineering tool. You’ll also understand how to use the orchestration and scheduling workflow to deploy machine learning models in batch. By the end of this book, you’ll have the skills to start working on data science projects confidently. By the end of this book, you’ll have the skills to start working on data science projects confidently.
Table of Contents (16 chapters)
Preface
12
12. Feature Engineering

Handling Missing Values

So far, you have looked at a variety of issues when it comes to datasets. Now it is time to discuss another issue that occurs quite frequently: missing values. As you may have guessed, this type of issue means that certain values are missing for certain variables.

The pandas package provides a method that we can use to identify missing values in a DataFrame: .isna(). Let's see it in action on the Online Retail dataset. First, you need to import pandas and load the data into a DataFrame:

import pandas as pd
file_url = 'https://github.com/PacktWorkshops/'\
           'The-Data-Science-Workshop/blob/'\
           'master/Chapter10/dataset/'\
           'Online%20Retail.xlsx?raw=true'
df = pd.read_excel(file_url)

The .isna() method returns a pandas...