“I tried Udacity, but quickly realized it wasn’t going to work—I didn’t have time during the day to watch full videos. Dataquest’s courses allowed me to advance bit by bit whenever I had a few minutes to spare.”

Luiz Zanini

Product Manager @Mastercard

Course overview

You’ll learn about regular expressions (regex), a powerful tool that allows you to match and manipulate text data with precision. You’ll also learn to work with JSON data, a common format you’ll encounter when pulling data from web APIs. Then you’ll dive into map and anonymous functions, two intermediate-to-advanced concepts in R that can speed up your data cleaning.

You’ll also learn how to resolve missing values in your data, a critical part of almost every data analysis project. Rather than dropping rows or columns, which reduces the amount of data you have to work with, you’ll learn statistical techniques to impute missing data, and you’ll also learn how to insert data from outside sources.

Best of all, you’ll learn by doing — you’ll practice and get feedback directly in the browser.

Key skills

  • Cleaning and manipulating text data using regex
  • Using map and anonymous functions
  • Resolving missing data
  • Advanced techniques for data cleaning

Course outline

Advanced Data Cleaning in R [4 lessons]

Regular Expression Basics 2h

Lesson Objectives
  • Employ regular expressions
  • Define Regex components like character classes and quantifiers
  • Implement regular expressions with the stringr package

Advanced Regular Expressions 2h

Lesson Objectives
  • Clean data by substituting regular expression matches
  • Employ lookarounds to include and exclude text before and after your regex match
  • Extract new columns from text data using capture groups

Map and Anonymous Functions 2h

Lesson Objectives
  • Read JSON files
  • Ceate and transform lists using map functions
  • Create anonymous functions

Working with Missing Data 2h

Lesson Objectives
  • Identify missing data using both code and visualizations
  • Resolve missing data using imputation
  • Fill missing values using external data

The Dataquest guarantee


Dataquest has helped thousands of people start new careers in data. If you put in the work and follow our path, you’ll master data skills and grow your career.


We believe so strongly in our paths that we offer a full satisfaction guarantee. If you complete a career path on Dataquest and aren’t satisfied with your outcome, we’ll give you a refund.

Master skills faster with Dataquest

Go from zero to job-ready

Go from zero to job-ready

Learn exactly what you need to achieve your goal. Don’t waste time on unrelated lessons.

Build your project portfolio

Build your project portfolio

Build confidence with our in-depth projects, and show off your data skills.

Challenge yourself with exercises

Challenge yourself with exercises

Work with real data from day one with interactive lessons and hands-on exercises.

Showcase your path certification

Showcase your path certification

Impress employers by completing a capstone project and certifying it with an expert review.

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Aaron Melton

Business Analyst at Aditi Consulting

“Dataquest starts at the most basic level, so a beginner can understand the concepts. I tried learning to code before, using Codecademy and Coursera. I struggled because I had no background in coding, and I was spending a lot of time Googling. Dataquest helped me actually learn.”


Jessica Ko

Machine Learning Engineer at Twitter

“I liked the interactive environment on Dataquest. The material was clear and well organized. I spent more time practicing then watching videos and it made me want to keep learning.”


Victoria E. Guzik

Associate Data Scientist at Callisto Media

“I really love learning on Dataquest. I looked into a couple of other options and I found that they were much too handhold-y and fill in the blank relative to Dataquest’s method. The projects on Dataquest were key to getting my job. I doubled my income!”

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