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Python Data Cleaning Cookbook

You're reading from   Python Data Cleaning Cookbook Prepare your data for analysis with pandas, NumPy, Matplotlib, scikit-learn, and OpenAI

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Product type Paperback
Published in May 2024
Publisher Packt
ISBN-13 9781803239873
Length 486 pages
Edition 2nd Edition
Languages
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Author (1):
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Michael Walker Michael Walker
Author Profile Icon Michael Walker
Michael Walker
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Table of Contents (14) Chapters Close

Preface 1. Anticipating Data Cleaning Issues When Importing Tabular Data with pandas 2. Anticipating Data Cleaning Issues When Working with HTML, JSON, and Spark Data FREE CHAPTER 3. Taking the Measure of Your Data 4. Identifying Outliers in Subsets of Data 5. Using Visualizations for the Identification of Unexpected Values 6. Cleaning and Exploring Data with Series Operations 7. Identifying and Fixing Missing Values 8. Encoding, Transforming, and Scaling Features 9. Fixing Messy Data When Aggregating 10. Addressing Data Issues When Combining DataFrames 11. Tidying and Reshaping Data 12. Automate Data Cleaning with User-Defined Functions, Classes, and Pipelines 13. Index

Identifying missing values

Since identifying missing values is such an important part of the workflow of analysts, any tool we use needs to make it easy to regularly check for such values. Fortunately, pandas makes it quite simple to identify missing values.

Getting ready

We will work with the National Longitudinal Survey (NLS) data in this chapter. The NLS data has one observation per survey respondent. Data for employment, earnings, and college enrollment for each year are stored in columns with suffixes representing the year, such as weeksworked21 and weeksworked22 for weeks worked in 2021 and 2022 respectively.

We will also work with the COVID-19 data again. This dataset has one observation for each country with total COVID-19 cases and deaths, as well as some demographic data for each country.

Data note

The National Longitudinal Survey of Youth is conducted by the United States Bureau of Labor Statistics. This survey started with a cohort of individuals...

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