#### Overview of this book

Businesses today operate online and generate data almost continuously. While not all data in its raw form may seem useful, if processed and analyzed correctly, it can provide you with valuable hidden insights. The Data Analysis Workshop will help you learn how to discover these hidden patterns in your data, to analyze them, and leverage the results to help transform your business. The book begins by taking you through the use case of a bike rental shop. You'll be shown how to correlate data, plot histograms, and analyze temporal features. As you progress, you’ll learn how to plot data for a hydraulic system using the Seaborn and Matplotlib libraries, and explore a variety of use cases that show you how to join and merge databases, prepare data for analysis, and handle imbalanced data. By the end of the book, you'll have learned different data analysis techniques, including hypothesis testing, correlation, and null-value imputation, and will have become a confident data analyst.
Preface
1. Bike Sharing Analysis
Free Chapter
2. Absenteeism at Work
3. Analyzing Bank Marketing Campaign Data
4. Tackling Company Bankruptcy
5. Analyzing the Online Shopper's Purchasing Intention
6. Analysis of Credit Card Defaulters
7. Analyzing the Heart Disease Dataset
8. Analyzing Online Retail II Dataset
9. Analysis of the Energy Consumed by Appliances
10. Analyzing Air Quality

# Data Preprocessing

Before proceeding onto univariate analysis, let's look at the unique values in the columns. The motive behind looking at the unique values in a column is to identify the subcategory in each column. By knowing the subcategory in each column, we would be in a position to understand which subcategory has a higher count or vice versa. For example, let's take the `EDUCATION` column. We are interested in finding what the different subcategories in the `EDUCATION` column are and which subcategory has the higher count; that is, do our customers have their highest education as `College` or `University`?

This step acts as a precursor before we build a profile of our customers.

Let's now find unique values in the `SEX` column.

We'll print the unique values in the `SEX` column and sort them in ascending order:

`print('SEX ' + str(sorted(df['SEX'].unique())))`

The output will be as follows:

`SEX [1, 2]`

The following code prints...