Load an existing notebook with local files

A Notebook Kit document on disk often references data files next to it. This recipe reads the document with Python, passes its text to Notebook.from_html, and embeds the referenced CSV so the widget carries its data wherever it renders.

The example writes the document and its data file to a temporary directory first, standing in for a notebook you already have.

from pathlib import Path
import tempfile

import marimo as mo
import observablejs as obs

base = Path(tempfile.mkdtemp(prefix="observable-source-"))
(base / "penguins.csv").write_text(
    "species,count\nAdelie,152\nChinstrap,68\nGentoo,124\n",
    encoding="utf-8",
)

source = """
<notebook theme="glacier">
  <script type="module">
const penguinCounts = FileAttachment("penguins.csv").csv({typed: true});
  </script>
  <script type="module">
Plot.barY(penguinCounts, {
  x: "species",
  y: "count",
  fill: "species",
  tip: {
    // This example references a theme variable used by mdx-marimo.
    // Replace it with a CSS color or remove `fill` in another host.
    fill: "var(--marimo-island-background)"
  }
}).plot({
  height: 260,
  color: {legend: true},
  y: {grid: true, label: "Penguins"}
})
  </script>
</notebook>
"""
source_path = base / "penguins.html"
source_path.write_text(source, encoding="utf-8")

notebook = obs.Notebook.from_html(
    source_path.read_text(encoding="utf-8"),
    base_path=source_path.parent,
    embed_file_attachments=True,
)
full_view = notebook.view()
mo.ui.anywidget(full_view)

The output renders species counts from the local CSV. The counts come from the Palmer Penguins dataset.

What this shows

• Path.read_text loads the document text before from_html constructs the source-backed notebook. The glacier theme and both cells come from that string.
• embed_file_attachments=True discovers the literal FileAttachment("penguins.csv") call, reads the file relative to the explicit base_path, and registers it as a data URL in notebook.attachments.
• Attachment discovery keeps the input document text unchanged. The attachment registry carries the embedded bytes.

Variations

• Add rewrite_imports=True when the document imports local JavaScript modules with relative specifiers. They are inlined recursively. See Add files and local modules.
• Leave embedding disabled when the page already serves the files at the same browser-relative paths.
• Override notebook values from Python by passing variables= to the constructor, exactly as with authored notebooks.