Course

Dictionaries, Frequency Tables, and Functions in Python

In this course, you’ll continue to learn the fundamentals of Python for data science with dictionaries, frequency tables, and Python functions. You’ll not only learn these concepts to organize your Python program for future analysis, you’ll also break it down into smaller units to make it more manageable when your program becomes larger and more complex.

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Part of the Data Analyst (Python), and Data Scientist (Python) paths.

4.8 (359 reviews)

20,444 learners enrolled in this course.

Beginner friendly
4 hours
Self paced
4 lessons

“At first, I kind of wanted videos. But it didn’t take long to realize that the Dataquest approach was working. I felt I was learning more by reading, and that it was giving me good practice for reading software documentation (which is rarely available in video tutorial form).”

Curtly Critchlow

Safety Security Officer @Nabi-KCL

Dictionaries, Frequency Tables, and Functions in Python

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Course overview

This course builds upon the fundamentals of Python taught in Introduction to Python Programming and For Loops and Conditional Statements in Python. You’ll learn how to create Python dictionaries, which are important data structures in Python that help gather elements for identification using a key. You’ll also learn how to build frequency tables, which help to display the frequencies of different categories (particularly useful for understanding the distribution of values in a dataset). Finally, you’ll learn how to write Python functions, which will help you perform a single, related action on a specific set of data.

Best of all, you’ll learn by doing — you’ll practice and get feedback directly in the browser. You’ll apply your skills to several guided projects involving realistic business scenarios to build your portfolio and prepare for your next interview.

Key skills

Creating Python dictionaries
Building frequency tables
Writing Python functions
Performing real-world data analysis tasks in an interactive coding environment

Course outline

Dictionaries, Frequency Tables, and Functions in Python [4 lessons]

Python Dictionaries 1h

Lesson Objectives

Create dictionaries
Index dictionaries
Define key-value pairs

Python Dictionaries and Frequency Tables 2h

Lesson Objectives

Update dictionary values
Check for values in a dictionary
Count with dictionaries
Loop over dictionaries

Python Functions: Using Built-in Functions and Creating Functions 1h

Lesson Objectives

Define the structure of a function
Create your own functions
Employ built-in functions
Return values from a function call

Python Functions: Arguments, Parameters, and Debugging 1h

Lesson Objectives

Reuse a function with different data inputs
Specify multiple function parameters
Employ keyword and positional arguments
Combine functions
Debug functions

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

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

Build your project portfolio

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

Challenge yourself with exercises

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

Showcase your path certification

Share the evidence of your hard work with your network and potential employers.

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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!”