This post documents how to set up Jupyter notebooks with Ruby support and embed them in blog posts.

Pre-conditions

gem install iruby
iruby register --force
brew install jupyter

Later, you can check the installed versions of IRuby with:

for version in $(rbenv versions --bare); do echo "=== Ruby $version ===" && RBENV_VERSION=$version gem list iruby 2>/dev/null | grep -E "^iruby" || echo "iruby not installed"; done

Local usage:

jupyter lab

Webbrowser usage: http://localhost:8888/lab

Workflow

1. Create your notebook (.ipynb file) - either via Jupyter Lab or by writing the JSON directly

2. Convert to HTML:

/opt/homebrew/opt/jupyterlab/bin/jupyter nbconvert --to html notebooks/your-notebook.ipynb

1. Extract the <main> content from the generated HTML

2. Add the Jupyter CSS to your site’s stylesheet (see assets/css/codeblock.css)

3. Embed the HTML directly in your blog post

Example

stdout

puts writes to stdout:

In [1]:

puts "This is stdout"

This is stdout

stderr

Two ways to write to stderr:

In [2]:

warn "Using warn"

Using warn

In [3]:

$stderr.puts "Using $stderr.puts"

Using $stderr.puts

Return value

The last expression's value shows with Out label:

In [4]:

"This is a return value"

Out[4]:

"This is a return value"

All three together

Output order: stdout, stderr, then return value:

In [5]:

puts "1. stdout via puts"
warn "2. stderr via warn"
$stderr.puts "3. stderr via $stderr.puts"
"4. return value"

1. stdout via puts

2. stderr via warn
3. stderr via $stderr.puts

Out[5]:

"4. return value"