npyquick 0.1.1

Quick GUI viewer for .npy / .npz arrays with image, table, and cross-section views

Why npyquick?

Researchers often need to quickly inspect .npy and .npz files without writing a notebook, launching an IDE, or remembering the array shape in advance.

npyquick is designed as a small, practical viewer for this job:

• open NumPy array files directly from the terminal or file manager
• inspect common scientific data layouts immediately
• stay lightweight and easy to understand
• avoid turning a simple array viewer into a full image-processing application

Installation

With pip:

pip install npyquick

With conda:

conda env create -f environment.yml
conda activate npyquick

Dependencies: Python ≥ 3.10, NumPy, SciPy, Matplotlib, and PySide6.

Usage

npyquick                        # open GUI
npyquick path/to/file.npy       # open with a file
npyquick path/to/file.npz       # open a multi-array archive

Files can be opened via File › Open (Ctrl+O) or by dragging and dropping onto the window.

Features

Image view

Preview 2D grayscale arrays and RGB arrays with interactive zoom, pan, colormap control, brightness adjustment, and a draggable cross-section profile.

Histogram view

Inspect value distributions with linear or log-scaled counts, robust range selection, summary statistics, and NaN / Inf reporting.

Line Plot view

Display 1D signals and paired (x, y) arrays with interactive zoom, pan, reset, and optional log-scaled axes.

Table view

Fallback preview for arrays that are not naturally displayed as images or line plots, including higher-dimensional, complex, object, scalar, or empty arrays.

.npz archives

When a .npz archive contains multiple arrays, npyquick shows a key selector with each array's name, shape, and dtype. Switching the selected key reloads the active view.

For detailed display rules, normalization behavior, downsampling, and performance limits, see Display behavior.

Keyboard shortcuts

Shortcut	Action
Ctrl+O	Open file
Ctrl+S	Export current figure
Ctrl+C	Copy current figure
Ctrl+Q	Quit
F5 / Ctrl+R	Reload current file
Ctrl+Tab	Switch to next enabled tab
Ctrl+Shift+Tab	Switch to previous enabled tab

Linux desktop integration

Register npyquick as the handler for .npy / .npz files so you can double-click them in your file manager, or right-click → Open With:

npyquick --install-desktop

This installs a .desktop entry, the .npy / .npz MIME types, and the app icon under ~/.local/share (user-level, no root). Then double-click a file, or test from the terminal:

xdg-open path/to/file.npy

To remove it:

npyquick --uninstall-desktop

Works on desktops that follow the freedesktop.org desktop-entry and MIME standards (GNOME, KDE Plasma, XFCE, Cinnamon, MATE). Some environments only show the new association after the file manager restarts or you log out and back in.

Manual setup (without the CLI command)

Create ~/.local/share/applications/npyquick.desktop, replacing the Exec= path with the output of which npyquick:

[Desktop Entry]
Type=Application
Name=npyquick
Comment=Open NumPy array files
Exec=/path/to/npyquick %f
Icon=npyquick
Terminal=false
Categories=Science;Utility;
MimeType=application/x-npy;application/x-npz;
StartupNotify=true

Register the MIME types by creating ~/.local/share/mime/packages/npyquick.xml:

<?xml version="1.0" encoding="UTF-8"?>
<mime-info xmlns="http://www.freedesktop.org/standards/shared-mime-info">
  <mime-type type="application/x-npy">
    <comment>NumPy array file</comment>
    <glob pattern="*.npy" weight="100"/>
  </mime-type>
  <mime-type type="application/x-npz">
    <comment>NumPy compressed archive</comment>
    <sub-class-of type="application/zip"/>
    <glob pattern="*.npz" weight="100"/>
  </mime-type>
</mime-info>

The sub-class-of and high glob weight matter for .npz: it is a ZIP container internally, so without them some desktops classify it as application/zip before the extension rule applies.

Then update the databases and set the default handler:

update-mime-database ~/.local/share/mime
update-desktop-database ~/.local/share/applications
xdg-mime default npyquick.desktop application/x-npy
xdg-mime default npyquick.desktop application/x-npz

Roadmap

• >2D array slicer
• Complex array support: real / imaginary / magnitude / phase

Contributing

Bug reports, feature requests, and suggestions are welcome — please open an issue.

The code in this repository is primarily written by an AI coding agent and reviewed by a human maintainer.

License

Copyright 2026 LiukDiihMieu

This project is licensed under the GNU General Public License v3.0 or later. Project logo and visual assets are included for use with this project. See the LICENSE file for details.