Python Data Viewer

• Thumbnails and Quick Look for .ipynb, .npy, and .npz
• Notebooks rendered with their cached outputs, plots and tracebacks included
• Not execution; read-only view of what the file already contains
• NumPy arrays as a sortable grid: float/int/bool/string dtypes, any shape
• .npz archives: every array listed, stored or compressed
• CSV export

Python Data Viewer renders notebooks as documents: markdown cells formatted, code cells syntax-aware, and the outputs that were saved with the notebook shown in place, including plots, results and tracebacks. Thumbnails render the notebook as a miniature page, cached matplotlib figures and all, so a folder of notebooks becomes visually distinguishable.

Nothing executes. The app reads the notebook JSON and displays what is already stored in it, which means opening an untrusted notebook carries none of the risk that actually running it would.

NumPy arrays open too. The .npy header format is small and well documented, so the reader covers float, integer, boolean and string dtypes, big-endian data and Fortran ordering, along with .npz archives whether stored or deflated. Numeric arrays display as a grid or as a viridis heatmap, with descriptive statistics and correlations available, and matrices get heatmap thumbnails.

Exports include the notebook as a jupytext-style .py script or as Markdown with its images extracted.

Requirements

Universal binary, so it runs on both Intel and Apple Silicon Macs.

• macOS 14 (Sonoma) or later
• Intel Mac or Apple Silicon (M1 or newer)

Installation

Download the file, unzip it, and copy it into your Applications folder. Open it once and it registers the Quick Look handler itself. Instructions are included with the download.

Apps downloaded here are signed by Apple, so you shouldn't see any Gatekeeper warnings.

Licence

What you may do: install and use the software, at no cost, on any Mac you own or control, for personal or business purposes.

What you may not do: sell, rent, lease, sublicense or otherwise charge anyone for the software; redistribute, repackage, bundle or host it for download (please point people at the official download page instead); or modify, adapt, translate, reverse-engineer, decompile or disassemble it, except to the limited extent applicable law expressly permits.

The software is licensed, not sold. All rights not expressly granted above are reserved by the copyright holder, who may offer future or paid versions under different terms.

Privacy

100% on-device. No accounts, no tracking, never connects to the internet, collects no data whatsoever.

Feedback

Please contact me with any feedback, issues, suggestions or requests!