jupyter-plainb

A JupyterLab extension to convert plaintext files to Jupyter notebooks

Installation

pip install jupyter-plainb

Requirements

• JupyterLab >= 4.0.0

Usage

1. Convert to Notebook

Select a .py or .md file in the file browser → right-click → Convert to Notebook submenu → pick a parser.

• If a .ipynb with the same base name already exists, a confirmation dialog asks before overwriting.

2. Open With (Direct notebook editor)

You can open and edit .py or .md files directly in the JupyterLab Notebook editor without generating a .ipynb file.

• Right-click a .py or .md file in the file browser → hover over Open With → select Notebook.
• Edits and cell runs save directly back to the original plaintext file format.

3. Convert to Plain Text (Reverse conversion)

Convert an existing .ipynb notebook back to one of the supported plaintext formats.

• Right-click a .ipynb file → hover over Convert to Plain Text submenu → select a target format.

4. Auto-convert on startup

Add plainTextNotebookConfig to jupyter_config.json (or JupyterLite's jupyter-lite.json):

{
  "jupyter-config-data": {
    "plainTextNotebookConfig": {
      "rules": [
        { "dir": "percent", "parser": "parsePy" },
        { "dir": "sphinx_gallery", "parser": "parseSphinxGallery" },
        { "dir": "markdown", "parser": "parseClassicMd" },
        { "dir": "myst", "parser": "parseMystMd" }
      ]
    }
  }
}

Each rule watches a directory and converts matching files on JupyterLab startup (skips files that already have a .ipynb sibling).

Supported formats

Parser	Menu label	File type	Format
parsePy	Percent format (.py)	.py	Jupytext percent
parseSphinxGallery	Sphinx Gallery (.py)	.py	Sphinx-Gallery
parseClassicMd	Classic Markdown (.md)	.md	Standard markdown — fenced code blocks become code cells
parseMystMd	MyST Notebook (.md)	.md	MyST-NB {code-cell} directives

Uninstall

pip uninstall jupyter-plainb

Contributing

See CONTRIBUTING.md