Book Image

Hands-On Data Preprocessing in Python

By : Roy Jafari
5 (2)
Book Image

Hands-On Data Preprocessing in Python

5 (2)
By: Roy Jafari

Overview of this book

Hands-On Data Preprocessing is a primer on the best data cleaning and preprocessing techniques, written by an expert who’s developed college-level courses on data preprocessing and related subjects. With this book, you’ll be equipped with the optimum data preprocessing techniques from multiple perspectives, ensuring that you get the best possible insights from your data. You'll learn about different technical and analytical aspects of data preprocessing – data collection, data cleaning, data integration, data reduction, and data transformation – and get to grips with implementing them using the open source Python programming environment. The hands-on examples and easy-to-follow chapters will help you gain a comprehensive articulation of data preprocessing, its whys and hows, and identify opportunities where data analytics could lead to more effective decision making. As you progress through the chapters, you’ll also understand the role of data management systems and technologies for effective analytics and how to use APIs to pull data. By the end of this Python data preprocessing book, you'll be able to use Python to read, manipulate, and analyze data; perform data cleaning, integration, reduction, and transformation techniques, and handle outliers or missing values to effectively prepare data for analytic tools.
Table of Contents (24 chapters)
1
Part 1:Technical Needs
6
Part 2: Analytic Goals
11
Part 3: The Preprocessing
18
Part 4: Case Studies

Outliers

Outliers, a.k.a. extreme points, are data objects whose values are too different than the rest of the population. Being able to recognize and deal with them is important from the following three perspectives:

  • Outliers may be data errors in data and should be detected and removed.
  • Outliers that are not errors can skew the results of analytic tools that are sensitive to the existence of outliers.
  • Outliers may be fraudulent entries.

We will first go over the tools we can use to detect outliers, and then we will cover dealing with them based on the analytic situation.

Detecting outliers

The tools we use for detecting outliers depend on the number of attributes involved. If we are interested in detecting outliers only based on one attribute, we call that univariate outlier detection; if we want to detect them based on two attributes, we call that bivariate outlier detection; and finally, if we want to detect outliers based on more than two attributes...