Marimo Tutorial (I): Your First Marimo Notebook

Reactive Python in 5 Minutes

In ***the previous article***, it explores generally what sets Marimo apart from Jupyter, when each tool shines, and how to choose the right one for your workflow. In this article, we will learn:

• How to install Marimo
• How reactive execution works
• How to write your first Marimo notebook

Install Marimo

There are different installation methods:

(1) Using pip

You can install it directly using pip as followings:

pip install marimo

Then start Marimo:

marimo

Your browser will open with a new notebook.

(2) Using uv (Recommand)

I recommend installing it with uv in a virtual environment:

1. Create virtual environment

uv venv

2. Activate the environment

Windows:

.venv\Scripts\activate

Linux

.venv/bin/activate

3. Marimo Installation

uv pip install marimo

Start the Tutorial

The best and quick way to learn Marimo Notebook is starting from its tutorial:

uv run marimo tutorial intro

Or:

marimo tutorial intro

Create Notebook

Create or edit notebooks with:

marimo edit

Create a New Notebook

Click Create a new notebook and then create a cell and write:

x = 10
x

Now add another cell:

y = x * 2
y

What’s happening?

• Marimo automatically tracks dependencies
• If you change x, y updates instantly
• No need to “run cells in order”

Try changing x = 20 → y becomes 40 automatically.

Why This Matters

In Jupyter:

• Running cells out of order can break results

In Marimo:

• Output always reflects the current state
• You cannot create an inconsistent notebook

Think of Marimo like Excel for Python code.

Key Takeaway

Marimo notebooks are always correct by construction.