WWT 2022 Release Notes: pywwt

The pywwt package is the official library for interfacing with WWT from the Python language. The WWT 2022 release of pywwt is a comprehensive update from older versions.

Installation & Getting Started

For guidance on installing pywwt and getting started using it, see the Researchers page.

New Support for JupyterLab

The WWT 2022 version of pywwt provides a new way to experience WWT in JupyterLab: in the form of the WWT research app through the new WWT JupyterLab extension. While pywwt could be used in “widget” mode before, the “app” mode is a vastly different — and superior — experience that is only possible when using JupyterLab.


The WWT 2022 version of pywwt now has its user interface powered by the WWT research app, rather than a bare-bones custom embed of the WWT engine. This means that many more operations can be done through the app UI rather than requiring Python coding. This changeover may break some historical usages of pywwt although the intention is to support old behaviors as fully as possible.

WWT Kernel Data Relay Now Required in Jupyter

When using pywwt in Jupyter environments, the wwt_kernel_data_relay Jupyter server extension is now required. It isn’t a hard dependency of pywwt since there are a variety of non-Jupyter cases where pywwt may be used.

New Asynchronous Support

The new release of pywwt has begun adding support for asynchronous operations using the Python language’s built-in systems. Only a few interfaces are supported at the moment. However, we expect more to be added as the communication between Python and the WWT web implementation is inherently asynchronous.

Support for New Engine Capabilities

In WWT 2022, pywwt adds support for the major new capabilities of the WWT WebGL Engine. In particular, it can load arbitrarily sized FITS datasets by automatically tiling them with Toasty. It can also load HiPS catalogs and imagesets, with the ability to fetch data from the former.

Bugfixes, Features, and More

The WWT 2022 release of pywwt includes a boatload of smaller bugfixes and new capabilities. See the detailed WWT 2022 components list for links to developer resources such as code repositories and comprehensive changelogs.

Go back to the WWT 2022 edition notes.

Copyright 2019-2023 the .NET Foundation. WorldWide Telescope is a fiscally sponsored project of NumFOCUS, a nonprofit dedicated to supporting the open-source scientific computing community.