Python for Altair: The Basics for Data People
Read every line of Altair code as plain Python, and fix it when it breaks.
You go at your own pace, with your Maestro beside you, 1:1, through the whole course: ask it anything, and it asks you questions too.
18 skills · 4 modules
$19
Comes with your Maestro, 1:1, for the whole course.
What will you be able to do?
Each box is a skill. The base is at the bottom, recognizing and explaining, and you work your way up to building something of your own and judging what works and why. Hover over a box to see what it builds on. Click it to see where I teach it and how your Maestro checks it.
- Analyze
- Apply
- Understand
Analyze
Read a Python traceback to locate and diagnose an error
Where I teach it: The Dot and the Parentheses · Reading a Traceback
Builds on:
- Call functions with positional and keyword arguments
- Run notebook cells and explain execution order and displayed output
Your Maestro asks you to break a problem down with it and saves it as evidence when you do.
Decompose an Altair snippet into imports, objects, methods, arguments, and strings
Where I teach it: Reading Altair as Python · Anatomy of an Altair Snippet
Builds on:
- Read and write method chains split across lines inside parentheses
- Call functions with positional and keyword arguments
- Import a library with an alias and explain namespaces such as alt.Chart
- Distinguish Python value types: int, float, str, bool, and None
Your Maestro asks you to break a problem down with it and saves it as evidence when you do.
Fix a broken Altair snippet by reading its error message
Where I teach it: Reading Altair as Python · Break It, Fix It
Builds on:
- Read a Python traceback to locate and diagnose an error
- Write and modify a basic Altair chart from a pandas DataFrame
Your Maestro asks you to break a problem down with it and saves it as evidence when you do.
Apply
Set up and run a Jupyter notebook in VS Code with pandas and Altair installed
Where I teach it: Python, Seen from R and Stata · Set Up Jupyter in VS Code
Your Maestro asks you to use it on a new case and saves it as evidence when you do.
Assign values to names and reuse them across cells
Where I teach it: Python, Seen from R and Stata · Variables: Names for Things
Builds on:
- Distinguish Python value types: int, float, str, bool, and None
- Run notebook cells and explain execution order and displayed output
Your Maestro asks you to use it on a new case and saves it as evidence when you do.
Write comparisons with ==, !=, <, > and tell assignment (=) apart from equality (==)
Where I teach it: Python, Seen from R and Stata · Comparisons: = Tells, == Asks
Builds on:
- Distinguish Python value types: int, float, str, bool, and None
- Assign values to names and reuse them across cells
Your Maestro asks you to use it on a new case and saves it as evidence when you do.
Call functions with positional and keyword arguments
Where I teach it: The Dot and the Parentheses · Functions and Keyword Arguments
Builds on:
- Distinguish Python value types: int, float, str, bool, and None
- Assign values to names and reuse them across cells
Your Maestro asks you to use it on a new case and saves it as evidence when you do.
Read and write method chains split across lines inside parentheses
Where I teach it: The Dot and the Parentheses · Objects, Methods, and Chaining
Builds on:
- Explain objects and methods: the dot as asking an object to do something
Your Maestro asks you to use it on a new case and saves it as evidence when you do.
Create lists and index them by position, counting from zero
Where I teach it: From Lists to DataFrames · Lists: Counting from Zero
Builds on:
- Assign values to names and reuse them across cells
- Distinguish Python value types: int, float, str, bool, and None
Your Maestro asks you to use it on a new case and saves it as evidence when you do.
Understand
Run notebook cells and explain execution order and displayed output
Where I teach it: Python, Seen from R and Stata · Cells and the Session's Memory
Builds on:
- Set up and run a Jupyter notebook in VS Code with pandas and Altair installed
Your Maestro asks you to explain it in your own words and saves it as evidence when you do.
Distinguish Python value types: int, float, str, bool, and None
Where I teach it: Python, Seen from R and Stata · Values and Types
Builds on:
- Run notebook cells and explain execution order and displayed output
Your Maestro asks you to explain it in your own words and saves it as evidence when you do.
Import a library with an alias and explain namespaces such as alt.Chart
Where I teach it: The Dot and the Parentheses · Imports: Borrowing a Library
Builds on:
- Run notebook cells and explain execution order and displayed output
Your Maestro asks you to explain it in your own words and saves it as evidence when you do.
Explain objects and methods: the dot as asking an object to do something
Where I teach it: The Dot and the Parentheses · Objects, Methods, and Chaining
Builds on:
- Call functions with positional and keyword arguments
- Import a library with an alias and explain namespaces such as alt.Chart
Your Maestro asks you to explain it in your own words and saves it as evidence when you do.
Explain how Altair's Python becomes Vega-Lite JSON, including the field:Q shorthand
Where I teach it: Reading Altair as Python · Python Turns into JSON
Builds on:
- Create and read dictionaries as key-value pairs
- Decompose an Altair snippet into imports, objects, methods, arguments, and strings
Your Maestro asks you to explain it in your own words and saves it as evidence when you do.
Ask your Maestro
Your Maestro is an AI that knows each course, page by page. Try it here free, in the free course "Exploratory Data Analysis: Your First 30 Minutes with a New Dataset".
You: Where do I start?
Your Maestro: From what you already know. Tell me what you've done with data, and I'll start this page from there.
Asking about: Answers from the page "How do I count the missing values in each column with pandas?"
Only this browser keeps what you ask here. How it works
What we'll cover
Python, Seen from R and Stata
- Welcome: Python for People Who Already Know Datareference
- Set Up Jupyter in VS Code
- Cells and the Session's Memory
- Values and Types
- Variables: Names for Things
- Comparisons: = Tells, == Asks
The Dot and the Parentheses
- Imports: Borrowing a Library
- Functions and Keyword Arguments
- Objects, Methods, and Chaining
- Reading a Traceback
From Lists to DataFrames
- Lists: Counting from Zero
- Dictionaries: Labels, Not Positions
- Loading and Looking at a DataFrame
- Selecting Columns and Filtering Rows
Reading Altair as Python
- Anatomy of an Altair Snippet
- Python Turns into JSON
- Your First Chart, Then Make It Yours
- Break It, Fix It
- Cheat Sheet and Next Stepsreference
How do I check what AI does? I teach it in Your AI and Your Data: Don't Let It Make Up the Number and Check what AI gives you in three steps.
What you get
- 4 modules and 19 pages, open whenever you want them.
Your Maestro for the whole course, who always knows which page you're on: you open it from there.
It works from this course's skills, the ones above.
Ask it how you're doing, and it tells you what you've already shown and what comes next.
Words you'll meet
In the lessons, tap one to see what it means, or ask your Maestro about it.
Who's teaching you
Sergio Sánchez
You already think in data: columns, filters, and scripts are familiar ground. This course teaches only the Python that Altair code uses, always by comparison with the tools you know. When you finish, you're ready for Effective Data Visualization with Altair.
I'm Sergio, chekos online. I'm a data architect, and I've spent more than ten years working with data in the Bay Area, mostly at mission-driven organizations: policy research first, then education, and now early childhood services. I grew up in Tijuana. In 2018 I started tacosdedatos to share what I was learning, and since then it's been a blog, a podcast, courses, guides, and a community. These days I spend a lot of my time building with AI agents and writing about how I organize my work around them. I share what I've learned; you take what's useful and make it yours.
The course in brief
| Price | $19 USD, paid once |
|---|---|
| Pages | 19 in 4 modules |
| Language | English, Spanish |
| Format | Online, at your own pace |
| Maestro | Your own 1:1 AI tutor for the whole course |
| Refund | In full, within 7 days |
See you in the course
Python for Altair: The Basics for Data People