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Data Wrangling with Python

You're reading from   Data Wrangling with Python Creating actionable data from raw sources

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Product type Paperback
Published in Feb 2019
Publisher Packt
ISBN-13 9781789800111
Length 452 pages
Edition 1st Edition
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Authors (2):
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Shubhadeep Roychowdhury Shubhadeep Roychowdhury
Author Profile Icon Shubhadeep Roychowdhury
Shubhadeep Roychowdhury
Dr. Tirthajyoti Sarkar Dr. Tirthajyoti Sarkar
Author Profile Icon Dr. Tirthajyoti Sarkar
Dr. Tirthajyoti Sarkar
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Table of Contents (12) Chapters Close

Data Wrangling with Python
Preface
1. Introduction to Data Wrangling with Python 2. Advanced Data Structures and File Handling FREE CHAPTER 3. Introduction to NumPy, Pandas, and Matplotlib 4. A Deep Dive into Data Wrangling with Python 5. Getting Comfortable with Different Kinds of Data Sources 6. Learning the Hidden Secrets of Data Wrangling 7. Advanced Web Scraping and Data Gathering 8. RDBMS and SQL 9. Application of Data Wrangling in Real Life Appendix

Identify and Clean Outliers


When confronted with real-world data, we often see a specific thing in a set of records: there are some data points that do not fit with the rest of the records. They have some values that are too big, or too small, or completely missing. These kinds of records are called outliers.

Statistically, there is a proper definition and idea about what an outlier means. And often, you need deep domain expertise to understand when to call a particular record an outlier. However, in this present exercise, we will look into some basic techniques that are commonplace to flag and filter outliers in real-world data for day-to-day work.

Exercise 79: Outliers in Numerical Data

In this exercise, we will first construct a notion of an outlier based on numerical data. Imagine a cosine curve. If you remember the math for this from high school, then a cosine curve is a very smooth curve within the limit of [1, -1]:

  1. To construct a cosine curve, execute the following command:

    from math import...
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